Study of Psychological and Motor Effects of Testosterone in Adolescents With XXY/Klinefelter Syndrome
Condition: Klinefelter Syndrome; XXY Syndrome
MeSH terms: Klinefelter Syndrome; Syndrome
Study type: Interventional

Summary: 
      The purpose of this study is to determine if testosterone replacement therapy leads to
      changes in psychological factors and/or motor skills in adolescent males with 47,XXY (also
      called Klinefelter syndrome). This study will also evaluate whether certain genetic factors
      of the X chromosome affect the psychological or motor features of XXY/Klinefelter syndrome.
    

Detailed description: 
      Klinefelter syndrome (47,XXY) is the most common chromosomal abnormality in humans and occurs
      in approximately 1 in 650 males. Testosterone deficiency develops during adolescence in the
      majority of individuals with XXY. However, there are no previous studies that evaluate the
      psychological and motor effects of testosterone replacement therapy in adolescents with XXY.

      The study researchers are interested in learning if testosterone therapy initiated in early
      puberty in XXY (KS) will lead to improvements in psychological and/or motor skills. They are
      also interested in learning if genetic variations of the androgen receptor gene or the
      parent-of-origin of the extra X chromosome influence the response to testosterone therapy.

      Specific psychological factors to be studied include verbal and nonverbal cognitive skills,
      attention, executive function (organization, problem-solving skills, inhibition), anxiety,
      language, self-esteem, and other behavioral factors. Motor skills to be studied include gross
      and fine motor skills, motor coordination, and motor planning.

      Participants in the study will be randomized to one of two treatment groups, receiving either
      testosterone gel or placebo, for 12 months. 60% of the study group will receive testosterone,
      and 40% will receive placebo.

      The research participants, parents/caregivers, and the members of the study team will be
      blinded to the treatment group, and will not know whether they are receiving testosterone gel
      or placebo treatments.

      The supervising endocrinologist for the study will not be blinded and will know which
      patients are in the testosterone and placebo groups. This will allow him to monitor results
      to determine if participants in the placebo group may develop a significant need for
      testosterone therapy during the study period. If this occurs, the patient will be switched to
      the testosterone group and will continue to be monitored in the study.

      All participants will be evaluated at the beginning of the study and at 1, 3, 6, and 12
      months. Travel costs are included. Evaluations will include a combination of psychological
      and motor skills testing, questionnaires completed by the parent/caregiver and study
      participant, physical examinations, and blood draws for safety monitoring and genetic
      studies.

      Participation in the trial will last one year and includes 5 clinic visits to the
      eXtraordinarY Kids Clinic at Children's Hospital Colorado in Denver.
    

Intervention name(s): Testosterone gel 1%; Placebo gel
Intervention type(s): Drug; Drug
Intervention description(s): Testosterone gel will be administered on a daily basis. The gel will be dispensed in a syringe, and the specific amount of gel to be applied each day will be determined by the study endocrinologist after reviewing labs.; The placebo gel will be administered on a daily basis. The gel will be dispensed in a syringe, and the specific amount of gel to be applied each day will be determined by the study endocrinologist.
Other intervention name(s): Androgel 1%
Intervention MeSH terms: Testosterone
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Treatment
Keywords: Klinefelter syndrome; XXY syndrome; Sex Chromosome Abnormality; Testosterone replacement therapy