Conditions: Klinefelter Syndrome
Keywords: Klinefelter syndrome androgen androgen oxandrolone
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 93
Healthy volunteers: no

Brief summary:
The purpose of this study is to evaluate the effects of low-dose androgen on the motor and cognitive development of boys with Klinefelter syndrome.

Detailed description:
Klinefelter syndrome (KS), a genetic disorder that affects males only, is characterized by having an extra X chromosome. The phenotype - or physical and learning features - includes testicular failure, tall stature, and specific cognitive and behavioral attributes such as diminished motor function, language-based learning difficulties, poor self-image, and shyness. The KS phenotype may be the result of androgen deficiency in utero, infancy, and childhood. For individuals with KS, androgen replacement is standard treatment in adolescence and adulthood but has not been used earlier in childhood or included in the standard medical care of KS children ages 4 to 12.

The purpose of this study is to examine the effects of androgen on learning and development in boys with KS. Researchers also want to determine if low-dose androgen replacement at an early age will improve some of the learning difficulties associated with the disorder. The overall goal of this study is to address questions regarding the relationship of early androgen deficiency to learning and motor function.

Participants in the study will be randomized to one of two treatment groups, receiving either oxandrolone (low-dose androgen) or placebo, for two years. All participants will be evaluated for safety at the beginning of the study and at 3, 6, 12, 18, and 24 months. Also at the beginning of the study and every 3 to 6 months thereafter (for a total of 6 visits), the researchers will perform a careful history and physical examination and a bone age X-ray, and obtain a blood sample.

Participation in the trial will last two years and includes 6 clinic visits.

Arms:
arm 1: Androgen oxandrolone: Oxandrolone, 0.6 \> mg/kg/day, orally, for 2 years. arm 2: An inactive substance.

Interventions: intervention 1: androgen oxandrolone intervention 2: placebo
Intervention descriptions: intervention 1: Oxandrolone ,06 \>mg/kg/day, orally, for 2 years intervention 2: an inactive substance

Protocol document:
Prot_SAP_000.pdf: 
 
 
 
 
 
 
 
 
 
 
 
 
Androgen Effects on Cognition in Klinefelter’s Syndrome 
NCT #: NCT00348946 
Date: January 1, 2011 


PROTOCOL: Androgen Effects on Cognition in Klinefelter’s Syndrome, Control # 02F476, Judith Ross, M.D.            2 
 
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PROTOCOL: Androgen Effects on Cognition in Klinefelter’s Syndrome, Control # 02F476, 
Judith Ross, M.D., Thomas Jefferson University 
 
Specific Aims 
Klinefelter’s syndrome (KS) (1) is a relatively common genetic disorder that 
occurs in 1/500 males, is defined by the abnormal chromosome karyotype 47,XXY, and 
includes a characteristic physical, cognitive, and behavioral phenotype. The KS physical 
phenotype is based on testicular failure and tall stature. The KS cognitive phenotype 
includes language-based learning difficulties, dyslexia, impaired attention, working 
memory, and executive abilities, and diminished muscle tone, strength, and 
coordination. The KS behavioral phenotype involves poor self-image, shyness and 
increased social anxiety, starting in childhood. 
The KS phenotype may be the result of androgen deficiency in utero, infancy and 
childhood. Androgen replacement is standard in adolescent and adult KS males but has 
not been used earlier in childhood. The goal of this randomized clinical trial is to study 
the effects of childhood androgen replacement on the KS neurocognitive and physical 
phenotypes. This randomized, placebo-controlled, longitudinal study tests a novel 
intervention in this population. We propose to replace androgen for two years in KS 
boys, between the ages of 4 and 12 years, using low, physiologic doses. We predict 
that multiple facets of the KS phenotype will improve with early androgen replacement: 
working memory, fine- and gross-motor coordination and speed, as well as self-esteem 
within the cognitive and behavioral phenotypes and muscle strength within the physical 
phenotype.  
Klinefelter’s syndrome is well suited for interventional studies because the 
disorder is relatively common in males, testicular failure is nearly universal, and the 
physical and cognitive phenotypic features have been characterized. Early androgen 
replacement in physiologic rather than pharmacologic dosages is a reasonable, 
appropriate, and safe consideration in this population. Therapeutic interventions for this 
relatively common disorder have not been forthcoming, and this represents a unique 
opportunity to replace a missing hormone and improve aspects of the cognitive and 
behavioral outcome.  The primary specific aim of this study will test the hypothesis that 
androgen replacement in childhood is beneficial by comparing cognition and behavior in 
androgen-treated versus placebo KS groups.  If successful, androgen replacement 
would commence early in childhood rather than adolescence or adulthood in 
Klinefelter’s syndrome.  
 
Specific Aim 1. Early androgen intervention, using a randomized clinical trial and 
treating for two years.  We will evaluate five primary outcome variables: general 
cognition, language summary score, Working memory/executive function summary 
score, Motor function summary score, and Self-image and social function summary 
score. 
Hypotheses regarding five primary outcomes: 
1. Certain aspects of the KS physical, neurocognitive and behavioral phenotype will 
improve with childhood androgen replacement therapy. 
a. The working memory summary score will improve after two years in the 
androgen-treated versus the placebo group. 


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b. The motor function summary score will improve after two years in the androgen-
treated versus the placebo group. 
c. The self-image summary score will improve after two years in the androgen-
treated versus the placebo group. 
 
BACKGROUND AND SIGNIFICANCE 
 
Klinefelter’s syndrome (KS), first described in 1942 on the basis of testicular 
failure (1), occurs only in males, and is characterized by the abnormal chromosome 
karyotype 47,XXY  (2).  Unlike other chromosomal trisomies, 47,XXY does not 
frequently cause spontaneous abortuses, most likely related to inactivation of the 
supranumerary X-chromosome occurring in many tissues. The KS phenotype includes 
testicular failure, tall stature, and a characteristic cognitive and behavioral phenotype. 
Other KS-associated phenotypic findings include increased risk for osteoporosis, breast 
cancer, autoimmune thyroid disorders, and Type II diabetes mellitus (3).  Most KS 
males were previously diagnosed in adolescence on the basis of testicular failure; 
however, increasing numbers are now detected through routine antenatal testing. 
Approximately 1 per 500-1000 males are affected (4).  Mosaicism for a normal 46,XY 
line occurs in approximately 10-20% of KS cases and is associated with improved 
prognosis.  
I. Testicular failure phenotype 
The clinical spectrum for the testicular failure phenotype ranges from near 
complete androgen deficiency and gonadal failure starting prenatally to mild androgen 
deficiency with azoospermia in adulthood. Many KS boys have fetal onset of gonadal 
failure manifest by small testes and penis early in infancy or childhood and early 
symptoms of androgen deficiency. Others manifest testicular failure in adolescence or 
adulthood. The in utero testosterone deficiency would likely occur in the last trimester 
because testosterone deficiency earlier in gestation would result in ambiguity of the 
external genitalia with hypospadias, which is not characteristic of KS. Rather, a burst of 
testosterone synthesis in the last trimester stimulates penile growth and it is this later 
testosterone growth-stimulating effect on the genitalia that is missing in KS males. 
A clue for diagnosis of KS earlier in infancy or childhood is the presence of small penis 
and testes, as exemplified by a set of twins discordant for KS (5). The testes and penis of 
the KS affected twin only, as well as in KS boys evaluated in childhood, were small at birth 
and throughout adolescence (5). Gonadotropins have generally been normal (low) in 
childhood and tend to rise by age 12-14 years in KS boys, similar to normal boys. 
However, normal gonadotropins in childhood do not necessarily indicate normal testicular 
function. Gonadotropins in girls with Turner syndrome who have early and severe ovarian 
failure are also normal in childhood and rise at age 10-12 years (6).  
Other signs of testicular failure in adolescence include gynecomastia, eunuchoidal 
body proportion with relatively longer legs and increased arm span, decreased facial, 
pubic, and body hair, decreased muscle mass, and feminine distribution of body fat. 
Testosterone levels measured prenatally and in infancy in a small number of KS males 
were decreased or normal (7) and remained low-normal in childhood and adulthood (5). 
Testicular biopsy specimens of KS infants demonstrate decreased germ cells. After 
puberty, hyalinization and fibrosis of the seminiferous tubules occurs with small testes and 


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azoospermia. Thus, the extra X chromosome affects both testicular germ cells and 
interstitial cells.    
II. Physical phenotype 
KS boys tend to be tall (average adult height of 186 cm) (8), starting in infancy 
and childhood, with disproportionately long legs and arms and relatively small head 
circumference SDS compared to height SDS (4, 5, 9, 10).  Their tall stature, mainly due 
to increased leg length, occurs in childhood and is likely related to 47,XXY males having 
a third copy of the X chromosome height determining gene, SHOX, as well as delayed 
epiphyseal fusion on the basis of decreased sex hormone levels. The SHOX (short 
stature homeobox) gene was first identified as a major human growth determinant from 
molecular analysis of sex chromosome abnormalities associated with short stature (11).  
Other sex chromosome trisomies, 47,XYY males and 47,XXX females, also tend be tall 
and have three copies of the SHOX gene (12). Skeletal anomalies associated with KS 
include osteoporosis, kyphosis, scoliosis, and pectus excavatum. KS males also have 
an increased risk for central obesity, starting in childhood (8).  
III. Neurocognitive and behavioral phenotype 
KS males also have a neurocognitive and behavioral phenotype that is 
expressed early in childhood and persists into adulthood. The main features include 1. 
language-based learning disabilities, 2. impaired working memory/executive function, 
and attention, 3. impaired motor abilities and 4. a characteristic personality style. 
Important information about the natural history of cognitive development in this 
population has been derived from several prospective, population-based longitudinal 
studies (8, 13-15). In general, global intelligence is less than siblings or controls (14), 
but Verbal IQ tends to be depressed relative to Performance IQ, both in children and 
adults (4, 14-18). In contrast, visual-spatial abilities are generally within the average 
range.   
1. Language-based learning disabilities: KS children and adults have 
impairment of selective aspects of receptive and expressive language processing. 
Delayed language and speech development is often detected by age 2-3 (8, 19, 20). 
These delays are predictive of later school problems with reading, spelling, writing, and 
problem solving that necessitate special education in childhood and adolescence (16, 
21).  Detailed studies of these language-based learning problems suggest underlying 
deficiencies in perception and short-term memory for sequential auditory information, 
limitations of phonemic processing, and poor understanding of grammatical and 
morphological aspects of language.  Associated expressive language problems include 
poor word-retrieval, depressed verbal fluency, and limitations in the capacity to 
formulate narrative constructions (14, 15, 18).  These difficulties in articulating and 
structuring language output as well as impaired verbal processing speed, and executive 
abilities persist into adulthood (17, 22-24).   
2. Working memory/executive and attention dysfunction: 
Neurodevelopmental anomalies of attentional systems are common. Attention deficits 
without hyperactivity (23,24) occur in KS males with executive dysfunction and 
problems with working memory.  Androgen replacement in KS males has been 
associated with improved fluency (25). Also, we previously demonstrated that androgen 
replacement in girls with Turner syndrome (10-14 years) who have androgen deficiency 
on the basis of ovarian failure was associated with improved working memory.  


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3. Motor abilities: KS children and adults also have diminished neuromuscular integration 
with impaired gross motor and fine motor skills and coordination, speed, dexterity and 
strength  (14, 26).  Young KS infants frequently had decreased motor tone and atypical 
movement patterns (27) and in childhood, balance, jumping and hopping are impaired (27). In 
addition, finger joint hypermobility and poor grasp specifically hinder writing skills (26). The 
motor impairments lead to impaired eye-hand coordination, clumsiness and poor athletic 
skills, which in turn, have a negative impact on socialization and self-image.  
 
Evidence of impaired simple motor function in girls with Turner syndrome (TS) and 
improvement with oxandrolone treatment for two years (Figure 1): We have included 
preliminary results from oxandrolone versus placebo treatment (0.06/mg/kg/day) of another 
androgen-deficient population: TS girls with ovarian failure, treated for 24 months [115]. 
Simple repetitive movement of the hand was assessed with subtests of the Physical and 
Neurological Evaluation for Soft Signs (PANESS). The time required to tap the thumb and 
forefinger 20 times and to tap the thumb to each of the 4 fingers sequentially 20 times was 
measured separately in the dominant (right only) and nondominant (left only) hands. Results 
were converted to SD scores using data from age- and handedness-matched control females. 
The change in SD scores at year 1 and year 2 are shown (Figure 1). The androgen-treated 
TS group had significantly improved simple repetitive movement of the hand (P < 0.05) after 
24, but not 12 months, compared to the placebo group. The mechanism of androgen effects 
may be through organization of neuronal processes and /or their growth and efficiency, 
perhaps in the pyramidal and nonpyramidal areas. We propose to use the same treatment 
duration (24 months) in the KS population because statistically significant changes in this 
simple motor task were observed after 24 but not 12 months of treatment.  
 
 
 
 
 
 
 
 
 
 
4. Personality development: There is also a psychosocial aspect of the KS phenotype 
affecting temperament and self-image.  By age three, KS boys are relatively quiet, 
passive, and socially withdrawn. They have increased worries and fears as well as 
difficulties with peer and sibling relationships (4). Their quiet, shy, and unassertive 
personalities place them at an increased risk for being bullied. Many boys have 
diminished self-esteem, as early as age 7, as well as diffuse anxiety and immaturity. 
Adolescents remain shy and immature with increased difficulty making social contact 
with others and decreased sexual libido (28, 29). During adolescence, KS males were 
more prone to impulsivity, outbursts, and conflict than controls (30), suggesting that this 
is a particularly difficult time for them. When adults have been followed long term, the 
cognitive and behavioral findings remain, but there is no increase in criminality, major 
psychopathology, or homosexuality, compared to hypogonadal 46,XY males (8, 22, 31). 
 
Figure 1: Change from baseline in simple repetitive  
movement SD Score* in girls with Turner syndrome  
treated with oxandrolone or placebo (X ± SEM) for 2 
 years *sum of PANESS 1-finger, 4-finger, dominant  
and nondominant hands 


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Certain psychiatric disorders including anxiety, depression, and psychosis are more 
common in KS (31) as well as a decreased likelihood for marriage.  One study 
comparing KS adult males with 46,XY hypogonadal males reported increased 
immaturity, fatigue, social isolation, and delayed sexual milestones in the KS population 
(22). Both populations were androgen-deficient, but the deficiency may be more severe 
or longstanding in the KS population. 
Poor motor coordination and athletic abilities impair normal development of 
positive self-esteem and increase anxiety and social isolation. The potential relationship 
of these social findings to the cognitive abnormalities is of great interest. Also, the 
contribution of androgen deficiency to this physical and social profile is unknown. Early 
testosterone replacement may increase muscle strength and coordination and may aid 
peer identification, self-esteem, and social function. 
IV. Determinants of brain development in KS males  
There appear to be early genetic effects of the additional X chromosome on brain 
growth and development, resulting in relative microcephaly at birth in KS males that 
persists and correlates with IQ. Support for relative microcephaly being related to 
genetic rather than hormonal mechanisms comes from the genetic model of 47,XXX 
females (4, 32) who are not androgen-deficient, but also tend to have relatively small 
heads. In addition, both KS males and 47,XXX females have increased speech and 
language problems, decreased coordination, and increased academic difficulties (12).       
Neuroimaging studies of KS males have shown reduced left temporal gray matter, 
consistent with the verbal and language deficits, and reduced amygdala volumes which may 
be related to psychopathology or behavioral dysfunction of KS males (25, 33).  The amygdala 
influences neuroendocrine, cognitive, and emotional aspects of information processing and is 
richly endowed with androgen and estrogen receptors. The volumes of the lateral ventricle and 
the amygdala increase with age in boys, particularly at puberty (34). This particular finding may 
provide a neuroanatomic basis for the KS shy temperament and passivity, while their poor 
phonemic processing and auditory memory may be related to alterations in left temporal lobe 
morphology (25).  
Language ability is asymmetrically organized in the brain, with nearly all right 
handers and 50% of left handers demonstrating left hemisphere dominance.  
Corresponding volumetric asymmetries of the left perisylvian cortex include a larger left 
planum temporale which may relate to increased neural representation devoted to the 
processing of sound-based representations of speech (35). Geschwind and Galaburda 
proposed that cerebral dominance for language is related to prenatal testosterone levels 
(36, 37). Neuropsychological findings in KS males (38-40) suggest anomalous 
development of cerebral hemispheric asymmetry with greater right hemisphere 
involvement, perhaps related to slower fetal brain growth rates and the failure of the left 
hemisphere to gain dominance in language processing (40). Phonemic event related 
potentials (ERP), which reflect increased processing time for linguistic information 
correlate with verbal IQ in KS (38). These relationships lead to the speculation that the 
slower processing of the phonemic ERP reflects anomalous neural processing of 
speech related to anomalous cortical localization. 
The etiology may be androgen deficiency in utero and early in life, excess X-
chromosome gene dosage effects, or both.  
  


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V. Testosterone effects on the brain, cognition, and behavior. 
Testosterone affects normal brain development in males and, in several models of 
androgen deficiency, androgen replacement improves specific aspects of cognition. Clearly, 
testosterone has organizational effects on the brain, both in utero and later in childhood and 
adulthood. Testosterone may also influence brain development through peripheral 
aromatization to estradiol. Whether reading and language deficits in KS are related to early 
androgen deficiency as opposed to genetic effects of the extra X chromosome is uncertain. 
That many KS infants are born with small phalluses and undescended testes would indicate 
early, in utero, testosterone deficiency. Another important testosterone effect on brain 
development may occur in infancy when there is normally a surge in testosterone, peaking 
during the second to fourth month of life in normal infant males. KS infants would presumably 
be lacking this testosterone surge. 
Both animal and human studies have shown clear-cut structural effects of androgen on 
subcortical nuclear regions such as the hypothalamic/preoptic area as well as forebrain 
regions that are related to behavior (41-43).  Androgen alterations during the perinatal period 
and puberty influence cognitive function and behavior in animal and human models. Gonadal 
steroids during human fetal development also affect cerebral dominance development and 
may lead to certain gender differences in cognition. Numerous examples support an 
association between androgen and spatial ability and to a lesser extent, working memory, in 
humans.  Males generally outperform females in visual-spatial tasks involving mental rotation, 
spatial perception, spatial visualization, and problem solving, which all rely to some extent on 
working memory (44). Neuropsychological impairment occurs in subjects with androgen 
deficiency.  Men with untreated, congenital, hypogonadotropic hypogonadism (IHH) have 
diminished production of testosterone as well as impaired spatial ability, verbal memory and 
attention relative to normal controls (45).  Yet, clear differences remain between 47,XXY KS 
males and 46,XY males with IHH, with the language- based learning disabilities being more 
characteristic of KS.  
Androgen replacement in KS males has been associated with improved fluency (39) and 
relatively increased left temporal cortical volumes (25). Working memory has been also been 
shown to respond to testosterone in elderly men who receive replacement therapy (46).The 
cerebral cortex may remain plastic until adulthood, permitting changes to be induced by 
testosterone. Against early testosterone deficiency being the sole etiology for the KS cognitive 
phenotype is the model of androgen-deficient males with hypogonadism but normal 
chromosomes, who do not generally suffer from dyslexia or impaired language abilities.   
In contrast, the association between the self-image and social phenotypes in KS and 
androgen deficiency is stronger. Androgen replacement may help in the areas of distractibility, 
mood, and psychosocial function (22, 47, 48). Verbal IQs in KS adolescents were positively 
related to earlier pubertal onset and higher testosterone levels (49). Most KS adults treated 
with testosterone benefited, reporting improved endurance and strength, concentration, 
learning ability, and mood (22). In addition, testosterone replacement in normal males with 
delayed puberty has been associated with improved self-perceived competence (47). What is 
not yet clear is what the optimal age for initiating testosterone treatment in KS males would 
be.  
VI. Genetic mechanisms 
The extra X chromosome in KS is usually acquired though non-disjunction during 
maternal or paternal gametogenesis, occurring in the egg (40-50%) or the sperm (50-


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60%), or through an error in mitotic division in the zygote (50-52).  Maternal inheritance 
of the extra X results from non-disjunction in the first (70%) or second (20%) meiosis or 
as a post-zygotic mitotic error (10%), with increased maternal age and reduced 
recombination also occurring (51).  
VII. Early androgen replacement in KS 
In summary, the hormonal and genetic contributions to the KS phenotype remain 
to be defined more clearly. Early diagnosis, together with early parental education and 
counseling, and earlier testosterone replacement may contribute to positive adjustment 
and reduce the negative social, emotional, and education impact of KS. Further studies 
linking the hormonal and genetic mechanisms will increase our understanding of the 
pathogenesis of KS and will permit more specific genetic counseling and interventions. 
The primary goal of this study is to test the effect of replacing the low levels of 
androgen in KS boys in an attempt to mimic the testosterone production that occurs 
normally in boys. Clinical support for androgen deficiency occurring earlier in childhood in 
KS boys than previously thought comes from the poor growth of the penis throughout 
childhood in these boys. The “standard of medical care” for initiating testosterone 
replacement therapy in KS males has typically been at age 11 or 12  years or older (59). 
Testosterone treatments in KS teenagers or adults results in appropriate virilization with 
increased muscle mass, more masculine body contour, increased body hair, penile 
growth, and amelioration of eunuchoidal tendencies.  
Typically, adult replacement doses of 200 mg of testosterone esters such as 
testosterone enanthate or cypionate are given every two weeks and newer formulations 
utilizing the intradermal or oral route are also available in relatively high adult-level, 
replacement dosages.  There are relatively few options for lower dose androgen 
replacement. One attractive consideration is the oral androgen oxandrolone which has 
been used safely in boys with delayed puberty and in girls with Turner syndrome for over 
twenty years and is FDA approved for children and adults for the indication of wasting (60-
62). Oxandrolone safely increased muscle mass in prepubertal boys with constitutional 
delay of growth (63). We propose a two-year clinical trial using two doses of oxandrolone 
versus placebo in young KS boys, ages 4-12 years (see below). 
 
RESEARCH DESIGN 
Study Design: This study consists of a clinical trial composed of an eligible subset of 
KS boys ages 4-12 years. The randomized design excludes bias in the assignment of 
patients to the treatment group and ensures optimal matching of the treatment group, 
which includes: 1. Oxandrolone (0.06 mg/kg PO, daily), or 2. oral placebo. The PI, 
patients, and research assistant will be blinded as to whether the oral medication is 
oxandrolone or placebo. The randomization is performed by the research pharmacy.  
Study Population: For the clinical trial, KS boys ages 4-12 years will be randomly 
assigned to one of two treatment groups (androgen versus no androgen). We will recruit 
180 males (60 per year for 3 years) assuming an approximate 30% drop out rate, to 
accrue a total of 120 patients for the clinical trial substudy.  
Patient Recruitment: The PI has the unique resource of a clinic at Thomas Jefferson 
University, where 60 KS boys are followed. All are untreated with any androgen.  We will also 
recruit additional patients by notifying patient groups and physicians about the study.  
 
 


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PROCEDURES OF THE STUDY  
 
 
I. Inclusion Criteria: 
1. Karyotype diagnosis of Klinefelter’s syndrome or Klinefelter’s variants, including 
48,XXYY and 48,XXXY 
2. Chronological ages 4 to 12 years 
3. No previous treatment with androgen or estrogen in past one year 
II. Exclusion Criteria: 
1. Major liver, kidney or other systemic disease 
2. Dual diagnoses including pervasive developmental delay or autism. 
3. Variant karyotypes including 46,XX males and 47,XYY  
    males 
4. A high level of mosaicism (more than 50% 46,XY cells) 
III. Study Outcome: 
Physical features 
We will document visible phenotypic features using a digital photography system. 
Specific physical features examined and tests used are as follows: 
1.Anthropometric measurements 
1.  Measurements.  The clinical assessment will include measurement of height, 
lower segment, and arm span. Subjects’ heights will be measured with a stadiometer. 
Measured or reported parental heights will also be recorded. Mid-parental height 
adjusted for the child’s sex (target height) will be calculated using the formula 0.5 x 
[father's height (cm) + mother's height (cm) + 13] (64). Target height z-scores are 
calculated for subjects from sex-adjusted mid-parental height obtained from the National 
Center for Health Statistics growth curve data (65). Arm span will be measured as the 
distance from right to left 3rd finger tips with patients facing the wall, with outstretched 
arms held parallel to the ground. Lower segment will be measured from the top of the 
symphysis pubis to the floor. Upper arm and lower leg circumferences will be measured.  
Results were converted to z-scores where possible using age- and gender-specific 
norms (65-67). 
2. Genitalia. We will measure penile length. Standards are available for penile 
growth in childhood and percentiles will be recorded (68). In addition, testicular size will 
be assessed with the Prader orchidometer and the measured volume will be recorded. 
3. Optional MRI SCAN: Patients with KS will be asked if they would have an MRI 
scan done at baseline and at or between the 18 and 24 month visits, when they are 
participating in the clinical trial.   
   The pathophysiology of KS includes changes in brain morphology and 
hemodynamic events.  The standard clinical MRI techniques do not provide functional 
information regarding perfusion, oxygenation and functional connectivity in the brain.  It 
is observed that physiological, cognitive and functional changes occur in addition to 
anatomical changes detectable using conventional protocols.  This is usually associated 
with abnormal vascularity and localized functional abnormalities.  In addition, white 
matter integrity and brain circuitry may also be affected.  Therefore, the ability to assess 
oxygenation, perfusion and functional connectivity and their changes under available 


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therapies in the brain of KS boys will greatly facilitate characterizing their stage of 
development, assessing their cognition and monitoring treatment.   
The goal of this procedure is to use a suite of complementary noninvasive, 
quantitative and functional MRI techniques to investigate cerebral blood supply, brain 
activity patterns and functional brain connections in patients with KS treated with 
Androgen or placebo, as part of the clinical trial.  Patients will be excluded if they have 
claustrophobia, pacemakers, metallic clips in the body, or orthodontic appliances or 
braces in the mouth. The procedure does not hurt or include any intravenous access or 
injections.  No sedation is involved. 
Laboratory studies 
1. Testicular function. Serum testosterone, follicle stimulating hormone (FSH), 
luteinizing hormone (LH), and salivary testosterone levels will be measured. Testicular 
failure is defined by castrate levels of FSH and LH in subjects at least ten years of age. 
Typically, the gonadotropins are suppressed in agonadal KS boys during childhood and 
do not rise until after age 10. Therefore, serum gonadotropin levels may not be a 
reliable index of testicular failure before age 10 years. Testicular function in boys <10 
yrs. old will be considered indeterminate if the gonadotropins are not elevated and will 
be reassessed in those subjects who reach age 10 by the end of the study. The 
presence of early testicular failure will be determined by measuring penile length and 
testicular size. 
2. Thyroid function. Free thyroxine (free T4) and thyroid stimulating hormone (TSH) 
will be measured because of an increased risk for thyroid disorders in KS. Standard 
criteria of the Jefferson clinical laboratory will be used to determine whether tests are 
abnormal. 
Radiographic studies 
1. Skeletal x-rays of the hands will be obtained for all subjects. Bone age will be 
determined according to the method of Greulich and Pyle (69). 
Cognitive Outcome summary scores (To be age-appropriate): 
1. General Cognition summary score (KS males, ages 2-60) 
a. The Differential Ability Scales-(DAS) 
2.  Language summary score (age-appropriate): 
Phonological 
a. Comprehensive test of Phonological Processing (CTOPP).  
.  
Verbal Memory  
a. California Verbal Learning Test-Children’s Version (CVLT)  
b.   Children’s Memory Scale (CMS)-story memory.   
Expressive 
a.   Expressive one word vocabulary test 
b. Rapid naming (NEPSY)  
c. Test of language Competence (TLC) – Oral Expression  
Receptive 
a. Peabody Picture Vocabulary Test (PPVT) 
b. Token Test  
3. Working memory/Executive function/Attention summary score 
a   Digit span backwards (DAS) 


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b. Connors’ Continuous Performance Test II (CPT II) and Kiddie Version (K-
CPT)  
c.   Connors’ Rating Scales-Revised  
d.   Verbal Fluencies-NEPSY(semantic) 
e.   Design fluency-NEPSY 
4. Motor function summary score  
Strength 
 
a.   Bruininks-Oseretsky Test of Motor Proficiency  
Fine motor 
a. Bruininks-Oseretsky Test of Motor Proficiency (BOTMP)-Fine Motor 
Composite  
Gross Motor 
a. Bruininks-Oseretsky Test of Motor Proficiency (BOTMP)-Gross motor 
composite 
b. NEPSY-praxis 
5. Self-image summary score-Males less than 21 years of age 
Social Function (Competence) 
a. Behavior Assessment System for Children (BASC) 
b. Child Behavior Checklist (CBCL) 
Affect and Behavior 
a.   Revised Child's Manifest Anxiety Scale (RCMAS)  
 
 
IV. Clinical trial substudy: Boys with Klinefelter’s syndrome will enter the study at ages 
4-12 years. At baseline, they will have a history and physical examination, cognitive and 
behavioral assessment, and further genetic evaluation. All potential subjects will have a 
full screening to determine eligibility before randomization. They will be randomized 
(double-blind) to one of two treatment groups: oxandrolone 0.06 mg/kg/day, or placebo 
control for  two years.  All subjects will be evaluated for safety at baseline, 3, 6, 12, 18 
and 24 months, and after one and two years for end-point efficacy (cognitive and 
behavioral assessment). 
 
The KS boys will be seen at 3-6-month intervals for the two-year duration of the 
study. On each visit, boys will receive a careful history and physical examination to 
include assessment of Tanner staging (73) for pubic hair development (Tanner 1 = 
prepubertal-Tanner 5 = fully mature) and measurement of penile length and testicular 
volume. At baseline, three, and every six months thereafter, we will measure height, 
weight, bone age (X-ray); fasting blood work to include complete blood count, serum 
glucose, liver function tests (SGPT), lipid panel, thyroid studies, testosterone, and free 
testosterone (the active form of testosterone) levels. LH, FSH and estradiol will be 
measured yearly. At baseline and after one year, each boy will undergo a battery of 
cognitive tests that will take approximately 5 to 7 hours (see below). 
 
The form of androgen will be the oral, nonaromatizable androgen oxandrolone. 
This androgen is FDA-approved for the indication of wasting and has been used safely 
for the past 30 years to stimulate growth in girls with Turner syndrome without virilization 
or major side effects. The dose, 0.06 mg/kg/day, was chosen because of the extensive 
previous experience with the dose of 0.06 mg/kg/day used in girls with Turner syndrome. 
Children will be monitored closely for signs of virilization including acne, voice changes, 


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development of pubic hair, and excessive bone age advancement. Since oxandrolone is 
nonaromatizable and cannot be converted to estradiol, we do not expect any feminizing 
side effects such as breast development to occur.  
 
Safety results necessitating an approximate 10-50% reduction in medication dose 
or stopping the medication: 
1. Bone age advancement exceeding 12 months per 6-month interval, with bone age 
exceeding chronologic age. 
2. Signs of early pubertal development for age, including pubic hair development in 
boys less than 8 years of age. 
3. Systolic blood pressure exceeding 95th %ile for age. 
4. Diastolic blood pressure exceeding 95th %ile for age. 
5. LDL cholesterol greater than159 mg/dl. 
6. HDL-C less than 20 mg/dl. 
7. SGPT exceeding twice the upper limit of normal. 
8. Dose can be lowered at the discretion of the investigator for other reasons such as          
rapid growth. 
 
 
The oxandrolone dosage cannot be reduced by precisely 50% because of the 
nature of the oxandrolone tablets that come in a single strength, 2.5 mg. The 2.5 mg pill 
is scored and could be accurately split to the 1.25 mg dose. The 1.25 mg dose cannot 
be accurately split further. Thus, according the criteria listed above, we could reduce the 
3.75 mg dose to 2.5 mg and the 2.5 mg dose to 1.25 mg. Dose reduction will therefore 
range from approximately 10-50%, depending on the weight of the child. If the dose 
needs to be reduced to less than 1.25 mg/day, we will change from daily to every other 
day dosing.  
 
 
If at any visit the child’s weight is greater than the 95th percentile, the 95th 
percentile weight in kg will be used to calculate the dose. If this dose reduction is 
implemented, then additional reductions would not be implemented at that visit for the 
other dose reduction criteria. At a single visit, if the dose of oxandrolone is reduced for 
one criterion, then the dosage is not reduced again for another study criterion. 
 
Safety results necessitating stopping the study: 
 
If at any point in the study, two or more patients develop severe liver function 
changes or hypertension, the study will be stopped. These changes have not occurred 
with oxandrolone used in a trial with 73 girls with Turner syndrome followed for up to 
four years and are therefore not expected.  
 
Criteria for Subject Withdrawal from the study and adverse event reporting: 
Subjects can withdraw from the study at any time for any reason. The PI may terminate a 
subject’s participation due to severe adverse events, noncompliance with the study, or 
concerns about safety. Safety data will be reviewed on an ongoing (blinded) basis by the PI. 
 
Study compliance: We will assess patient compliance by having the families fill out study 
cards when they administer all medications and return the cards as well as all used and 


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unused study materials at the time of their visit. All pills dispensed and returned will be 
counted and recorded. We are currently using this procedure in other ongoing studies and 
have found that it is effective. 
 
Post-Study Visit: Per the recommendation of the Data Safety and Monitoring Board (DSMB) 
all study participants will be invited back for a post-study visit. This visit will occur 
approximately 6-28 months post-study for patients who have enrolled in the study. The post-
study visit will include a history, physical examination, fasting blood work, bone age x-ray, 
photographs, and cognitive testing. Patients will be reimbursed $50.00 for completion of the 
visit. Patients who are unable to travel to a post-study visit or who live farther than driving 
distance will be asked to have a blood sample drawn locally and sent to our office in 
Philadelphia.  
 
ANALYSIS  
 
The analysis will be performed in consultation with the statistician, Dr. Harvey 
Kushner who has been collaborating with Dr. Ross for the past 15 years. The analyses 
described below will include 2 groups of KS boys. All results will be based on gender and 
age-specific standardized scores. Analysis for safety will be performed at 3, 6, 12, 18, and 
24 months and an efficacy analysis for summary scores encompassing all cognitive and 
behavioral variables will be performed at 12 and 24 months.  
I. Safety:  An analysis of safety parameters will be performed for the 3, 6, 12, 18 and 24 
month values based on a two-way ANCOVA, adjusting for baseline values, comparing 
the active treatment group versus the placebo.  The safety parameters are:  systolic and 
diastolic blood pressure, HDL, LDL cholesterol, liver function (ALT), bone age 
advancement, or signs of puberty (pubic hair).  
II. Primary efficacy (Hypotheses 1 a,b,c):  The analysis comparing androgen-treated to 
placebo-treated KS subjects for the one and two-year measurements will be based on the 
analysis of covariance (ANCOVA). We will perform a two-way ANCOVA for the five primary 
outcome measures at 12 and 24 months, comparing  the treatment group versus the placebo, 
adjusting for baseline values and socioeconomic status.  There will be a total of 5 summary 
scores. Each score will be the sum of component  z-scores based on gender and age-specific 
normative values. The summary scores include 1. General cognition, 2. Language, 3. Working 
memory/executive function and attention, 4. Motor function, and 5. Self-image and behavior. 
The alpha level for statistical significance will be set at 0.01 for each of the five primary 
outcome results.  
Data Management and processing: Dr. Harvey Kushner, the biostatistician, will perform all 
statistical analyses. All data will be entered using a custom program written for the project. An 
on site data manager will oversee the data collection and entry, and quality control. The 
database will be visual dBase for data entry and will be converted to SAS (version 8.2) for 
statistical analyses. Dr. Kushner will produce the data source tables, summary data tables as 
well as perform the designated analyses.  All entered data will be manually compared to the 
source documents for accuracy. Additional checks for consistency within and between 
records will be built into source documents for accuracy. Baseline and follow-up data will be 
collected on case report forms.  
  
Power Analysis 


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This RCT is based on a randomized block design, comparing  the treatment 
group with the placebo group composed of males who all have Klinefelter's syndrome 
and are between the ages of 4 and 12 years of age. Based on previously published data 
for word fluency performance in KS males, receiving or not receiving testosterone (25), 
we performed a power analysis and determined that we will have > 90% power, at alpha 
= 0.05, two-tailed, to detect significant androgen effects on working memory/executive 
function for each active treatment group versus the placebo group, with n=20 in each 
group. 
 
 
 
 
 
 
References 
 
1. 
Klinefelter H, Reifenstein, EC, Albright, F 1942 Syndrome characterized by 
gynecomastia, aspermatogenesis, without A-Leydigism and increased excretion of 
follicle stimulating hormone. J Clin Endocr Metab 2:615-627 
2. 
Bradbury J, Bunge, RG, Boccabella, RA 1956 Chromatin test in Klinefelter's 
syndrome. J Clin Endocrinol Metab 16:689 
3. 
Price WH, Clayton JF, Wilson J, Collyer S, De Mey R 1985 Causes of death in X 
chromatin positive males (Klinefelter's syndrome). J Epidemiol Community Health 
39:330-6. 
4. 
Ratcliffe SG, Murray L, Teague P 1986 Edinburgh study of growth and development 
of children with sex chromosome abnormalities. III. Birth Defects Orig Artic Ser 22:73-
118 
5. 
Ratcliffe SG 1982 The sexual development of boys with the chromosome constitution 
47,XXY (Klinefelter's syndrome). Clin Endocrinol Metab 11:703-16. 
6. 
Conte FA, Grumbach MM, Kaplan SL 1975 A diphasic pattern of gonadotropin 
secretion in patients with the syndrome of gonadal dysgenesis. J Clin Endocrinol Metab 
40:670-4. 
7. 
Sorensen K, Nielsen J, Wohlert M, Bennett P, Johnsen SG 1981 Serum testosterone 
of boys with karyotype 47,XXY (Klinefelter's syndrome) at birth. Lancet 2:1112-3. 
8. 
Ratcliffe S 1999 Long-term outcome in children of sex chromosome abnormalities. Arch 
Dis Child 80:192-5. 
9. 
Ratcliffe SG, Masera N, Pan H, McKie M 1994 Head circumference and IQ of children 
with sex chromosome abnormalities. Dev Med Child Neurol 36:533-44. 
10. 
Caldwell PD, Smith DW 1972 The XXY (Klinefelter's) syndrome in childhood: 
detection and treatment. J Pediatr 80:250-8. 
11. 
Rao E, Weiss B, Fukami M, et al. 1997 Pseudoautosomal deletions encompassing a 
novel homeobox gene cause growth failure in idiopathic short stature and Turner 
syndrome. Nat Genet 16:54-63. 
12. 
Linden MaB, BG 2002 Fifty-one prenatally diagnosed children and adolescents with sex 
chromosome abnormalities. Am J Med Genet 110:11-18 


PROTOCOL: Androgen Effects on Cognition in Klinefelter’s Syndrome, Control # 02F476, Judith Ross, M.D.            
15 
 
15 
13. 
Rovet J, Netley C, Bailey J, Keenan M, Stewart D 1995 Intelligence and achievement 
in children with extra X aneuploidy: a longitudinal perspective. Am J Med Genet 60:356-
63. 
14. 
Robinson A, Bender BG, Borelli JB, Puck MH, Salbenblatt JA, Winter JS 1986 Sex 
chromosomal aneuploidy: prospective and longitudinal studies. Birth Defects Orig Artic 
Ser 22:23-71 
15. 
Walzer S, Bashir AS, Silbert AR 1990 Cognitive and behavioral factors in the learning 
disabilities of 47,XXY and 47,XYY boys. Birth Defects Orig Artic Ser 26:45-58 
16. 
Rovet J, Netley C, Keenan M, Bailey J, Stewart D 1996 The psychoeducational profile 
of boys with Klinefelter’s syndrome. J Learn Disabil 29:180-96. 
17. 
Porter ME, Gardner HA, DeFeudis P, Endler NS 1988 Verbal deficits in Klinefelter 
(XXY) adults living in the community. Clin Genet 33:246-53. 
18. 
Graham JM, Jr., Bashir AS, Stark RE, Silbert A, Walzer S 1988 Oral and written 
language abilities of XXY boys: implications for anticipatory guidance. Pediatrics 
81:795-806. 
19. 
Robinson A, Puck M, Pennington B, Borelli J, Hudson M 1979 Abnormalities of the 
sex chromosomes: a prospective study on randomly identified newborns. Birth Defects 
Orig Artic Ser 15:203-41 
20. 
Bender BG, Linden MG, Robinson A 1993 Neuropsychological impairment in 42 
adolescents with sex chromosome abnormalities. Am J Med Genet 48:169-73. 
21. 
Leonard MF, Sparrow S 1986 Prospective study of development of children with sex 
chromosome anomalies: New Haven Study IV. Adolescence. Birth Defects Orig Artic 
Ser 22:221-49 
22. 
Nielsen J, Pelsen B 1987 Follow-up 20 years later of 34 Klinefelter males with 
karyotype 47,XXY and 16 hypogonadal males with karyotype 46,XY. Hum Genet 
77:188-92. 
23. 
Geschwind DH, Boone KB, Miller BL, Swerdloff RS 2000 Neurobehavioral phenotype 
of Klinefelter’s syndrome. Ment Retard Dev Disabil Res Rev 6:107-16 
24. 
Boone KB, Swerdloff RS, Miller BL, et al. 2001 Neuropsychological profiles of adults 
with Klinefelter’s syndrome. J Int Neuropsychol Soc 7:446-56. 
25. 
Patwardhan AJ, Eliez S, Bender B, Linden MG, Reiss AL 2000 Brain morphology in 
Klinefelter’s syndrome: extra X chromosome and testosterone supplementation. 
Neurology 54:2218-23. 
26. 
Salbenblatt JA, Meyers DC, Bender BG, Linden MG, Robinson A 1987 Gross and 
fine motor development in 47,XXY and 47,XYY males. Pediatrics 80:240-4. 
27. 
Samango-Sprouse C 2001 Mental development in polysomy X Klinefelter’s syndrome 
(47,XXY; 48,XXXY): effects of incomplete X inactivation. Semin Reprod Med 19:193-
202. 
28. 
Ratcliffe SG, Bancroft J, Axworthy D, McLaren W 1982 Klinefelter's syndrome in 
adolescence. Arch Dis Child 57:6-12. 
29. 
Stewart DA, Bailey JD, Netley CT, Rovet J, Park E 1986 Growth and development 
from early to midadolescence of children with X and Y chromosome aneuploidy: the 
Toronto Study. Birth Defects Orig Artic Ser 22:119-82 
30. 
Netley C 1991 Personality in 47, XXY males during adolescence. Clin Genet 39:409-18. 
31. 
Mandoki MW, Sumner GS, Hoffman RP, Riconda DL 1991 A review of Klinefelter's 
syndrome in children and adolescents. J Am Acad Child Adolesc Psychiatry 30:167-72. 


PROTOCOL: Androgen Effects on Cognition in Klinefelter’s Syndrome, Control # 02F476, Judith Ross, M.D.            
16 
 
16 
32. 
Ratcliffe SG, Read G, Pan H, Fear C, Lindenbaum R, Crossley J 1994 Prenatal 
testosterone levels in XXY and XYY males. Horm Res 42:106-9 
33. 
Patwardhan AJ, Brown WE, Bender BG, Linden MG, Eliez S, Reiss AL 2002 
Reduced size of the amygdala in individuals with 47,XXY and 47,XXX karyotypes. Am 
J Med Genet 114:93-8. 
34. 
Lange N, Giedd JN, Castellanos FX, Vaituzis AC, Rapoport JL 1997 Variability of 
human brain structure size: ages 4-20 years. Psychiatry Res 74:1-12. 
35. 
Galaburda AM, LeMay M, Kemper TL, Geschwind N 1978 Right-left asymmetrics in 
the brain. Science 199:852-6. 
36. 
Geschwind N, Galaburda AM 1985 Cerebral lateralization. Biological mechanisms, 
associations, and pathology: II. A hypothesis and a program for research. Arch Neurol 
42:521-52. 
37. 
Geschwind N, Galaburda AM 1985 Cerebral lateralization. Biological mechanisms, 
associations, and pathology: I. A hypothesis and a program for research. Arch Neurol 
42:428-59. 
38. 
Netley C, Taylor MJ, Molan M 1995 Event-related potentials (ERPs) and intelligence 
in neonatally identified 47,XXY males. Clin Genet 47:150-4. 
39. 
Alexander GM, Swerdloff RS, Wang C, et al. 1998 Androgen-behavior correlations in 
hypogonadal men and eugonadal men. II. Cognitive abilities. Horm Behav 33:85-94. 
40. 
Netley C, Rovet J 1984 Hemispheric lateralization in 47,XXY Klinefelter's syndrome 
boys. Brain Cogn 3:10-8. 
41. 
Juraska JM 1991 Sex differences in "cognitive" regions of the rat brain. 
Psychoneuroendocrinology 16:105-9 
42. 
Matsumoto A 1991 Synaptogenic action of sex steroids in developing and adult 
neuroendocrine brain. Psychoneuroendocrinology 16:25-40 
43. 
Rasika S, Nottebohm F, Alvarez-Buylla A 1994 Testosterone increases the recruitment 
and/or survival of new high vocal center neurons in adult female canaries. Proc Natl 
Acad Sci U S A 91:7854-8. 
44. 
Linn MC, Petersen AC 1985 Emergence and characterization of sex differences in 
spatial ability: A meta-analysis. Child Develop 56:1479-1498 
45. 
Hier DB, Crowley WF, Jr. 1982 Spatial ability in androgen-deficient men. N Engl J 
Med 306:1202-5. 
46. 
Janowsky JS, Chavez B, Orwoll E 2000 Sex steroids modify working memory. J Cogn 
Neurosci 12:407-14 
47. 
Schwab J, Kulin HE, Susman EJ, et al. 2001 The role of sex hormone replacement 
therapy on self-perceived competence in adolescents with delayed puberty. Child Dev 
72:1439-50. 
48. 
Wang C, Alexander G, Berman N, et al. 1996 Testosterone replacement therapy 
improves mood in hypogonadal men--a clinical research center study. J Clin Endocrinol 
Metab 81:3578-83. 
49. 
Netley C 1992 Time of pubertal onset, testosterone levels and intelligence in 47,XXY 
males. Clin Genet 42:31-4. 
50. 
Harvey J, Jacobs PA, Hassold T, Pettay D 1990 The parental origin of 47,XXY males. 
Birth Defects Orig Artic Ser 26:289-96 


PROTOCOL: Androgen Effects on Cognition in Klinefelter’s Syndrome, Control # 02F476, Judith Ross, M.D.            
17 
 
17 
51. 
MacDonald M, Hassold T, Harvey J, Wang LH, Morton NE, Jacobs P 1994 The 
origin of 47,XXY and 47,XXX aneuploidy: heterogeneous mechanisms and role of 
aberrant recombination. Hum Mol Genet 3:1365-71. 
52. 
Iitsuka Y, Bock A, Nguyen DD, Samango-Sprouse CA, Simpson JL, Bischoff FZ 
2001 Evidence of skewed X-chromosome inactivation in 47,XXY and 48,XXYY 
Klinefelter’s patients. Am J Med Genet 98:25-31. 
53. 
Ross JL, Roeltgen D, Kushner H, Wei F, Zinn AR 2000 The Turner syndrome-
associated neurocognitive phenotype maps to distal Xp. Am J Hum Genet 67:672-81 
54. 
Sarkar R, Marimuthu KM 1983 Association between the degree of mosaicism and the 
severity of syndrome in Turner mosaics and Klinefelter mosaics. Clin Genet 24:420-8. 
55. 
Jacobs PA, Hassold TJ, Whittington E, et al. 1988 Klinefelter's syndrome: an analysis 
of the origin of the additional sex chromosome using molecular probes. Ann Hum Genet 
52:93-109. 
56. 
Skuse DH 2000 Imprinting, the X-chromosome, and the male brain: explaining sex 
differences in the liability to autism. Pediatr Res 47:9-16 
57. 
Skuse DH, James RS, Bishop DV, et al. 1997 Evidence from Turner's syndrome of an 
imprinted X-linked locus affecting cognitive function. Nature 387:705-708 
58. 
Ratcliffe SG, Butler GE, Jones M 1990 Edinburgh study of growth and development of 
children with sex chromosome abnormalities. IV. Birth Defects Orig Artic Ser 26:1-44 
59. 
Smyth CM, Bremner WJ 1998 Klinefelter’s syndrome. Arch Intern Med 158:1309-14. 
60. 
Fox-Wheeler S, Heller L, Salata CM, et al. 1999 Evaluation of the effects of 
oxandrolone on malnourished HIV-positive pediatric patients. Pediatrics 104:e73. 
61. 
Wilson DM, McCauley E, Brown DR, Dudley R 1995 Oxandrolone therapy in 
constitutionally delayed growth and puberty. Bio- Technology General Corporation 
Cooperative Study Group. Pediatrics 96:1095-100. 
62. 
Schroor EJ, van Weissenbruch MM, Knibbe P, Delemarre-van de Waal HA 1995 
The effect of prolonged administration of an anabolic steroid (oxandrolone) on growth in 
boys with constitutionally delayed growth and puberty. Eur J Pediatr 154:953-7. 
63. 
Papadimitriou A, Preece MA, Rolland-Cachera MF, Stanhope R 2001 The anabolic 
steroid oxandrolone increases muscle mass in prepubertal boys with constitutional delay 
of growth. J Pediatr Endocrinol Metab 14:725-7. 
64. 
Tanner JM, Goldstein H, Whitehouse RH 1970 Standards for children's height at ages 
2-9 years allowing for heights of parents. Arch Dis Child 45:755-62. 
65. 
Hamill PV, Drizd TA, Johnson CL, Reed RB, Roche AF, Moore WM 1979 Physical 
growth: National Center for Health Statistics percentiles. Am J Clin Nutr 32:607-29. 
66. 
Hall JG, Froster-Iskenius, Ursula G., Allanson, Judith E. 1995 Handbook of Normal 
Physical Measurements. Oxford University Press, Oxford 
67. 
McKusick VA 1972 Heritable disorders of connective tissue. The C. V. Mosby 
Company, Saint Louis 
68. 
Jones DL 1997 Smith's Recognizable Patterns of Human Malformation, 5th ed. W.B. 
Saunders, Philadelphia 
69. 
Greulich WaP, S I 1959 Radiographic Atlas of Skeletal Development of the Hand and 
Wrist. Stanford University Press, Stanford, California 
70. 
Hook E 1977 Exclusion of chromosomal mosaicism: tables of 90%, 95%, and 99% 
confidence limits and comments on use. Am J Hum Genet 29:94-97 


PROTOCOL: Androgen Effects on Cognition in Klinefelter’s Syndrome, Control # 02F476, Judith Ross, M.D.            
18 
 
18 
71. 
Allen RC, Zoghbi HY, Moseley AB, Rosenblatt HM, Belmont JW 1992 Methylation 
of HpaII and HhaI sites near the polymorphic CAG repeat in the human androgen-
receptor gene correlates with X chromosome inactivation. Am J Hum Genet 51:1229-39 
72. 
Plenge RM, Stevenson RA, Lubs HA, Schwartz CE, Willard HF 2002 Skewed X-
chromosome inactivation is a common feature of X-linked mental retardation disorders. 
Am J Hum Genet 71:168-73. 
73. 
Marshall WA TJ 1993 Variations in pattern of pubertal changes in girls. Arch Dis Child 
44:291-303