TaoMedAI/RareMedData huggingface dataset:
Monoclonal mast cell activation syndrome (ORPHA:529468)
A rare hematologic disease characterized by symptoms of mast cell activation in the absence of cutaneous findings, as well as absence of diagnostic criteria of systemic mastocytosis with tryptase levels of less than 20 ng/ml and normal to low burden of mast cells. Bone marrow biopsy reveals the presence of monoclonal mast cells carrying the KIT D816V mutation and/or expressing CD25. Patients present with recurrent episodes of flushing, headache, hypotension, abdominal cramping, nausea, diarrhea, cardiac arrhythmias, bronchoconstriction, and bleeding diathesis, among others.
Mononen-Karnes-Senac syndrome (ORPHA:2565)
Mononen-Karnes-Senac syndrome is characterized by skeletal dysplasia associated with finger malformations (brachydactyly with short and abducted thumbs, short index fingers, and markedly short and abducted great toes), variable mild short stature, and mild bowleg with overgrowth of the fibula. It has been described in two males, their mothers, and a maternal aunt. Females are less severely affected than males. X-linked dominant inheritance is suggested.
Monosomy 13q14 (ORPHA:1587)
Monosomy 13q14 is a rare chromosomal anomaly syndrome, resulting from a partial deletion of the long arm of chromosome 13, characterized by developmental delay, variable degrees of intellectual disability, retinoblastoma and craniofacial dysmorphism (incl. micro/dolichocephaly, high and broad forehead, prominent eyebrows, thick, anteverted ear lobes, short nose with a broad nasal bridge and bulbous tip, prominent philtrum, large mouth with thin upper lip and thick, everted lower lip). Other features reported include high birth weight, macrocephaly, pinealoma, hepatomegaly, inguinal hernia and cryptorchidism.
Monosomy 13q34 (ORPHA:96168)
Monosomy 13q34 is a rare chromosomal anomaly syndrome, resulting from the partial deletion of the long arm of chromosome 13, principally characterized by global developmental delay, mild intellectual disability, obesity and mild craniofacial dysmorphism (microcephaly, wide rectangular forehead, downslanting palpebral fissures, mild ptosis, prominent nose with long nasal bridge and broad tip, small chin). Other variable reported features include congenital heart defects, hand and foot anomalies (e.g. polydactyly) and agenesis of the corpus callosum.
Monosomy 18p (ORPHA:1598)
Monosomy 18p refers to a chromosomal disorder resulting from the deletion of all or part of the short arm of chromosome 18.
Epidemiology
The incidence is estimated to be about 1:50,000 live-born infants.
Clinical description
In the commonest form of the disorder, the dysmorphic syndrome is very moderate and non-specific. The main clinical features are short stature, round face with short philtrum, palpebral ptosis and large ears with detached pinnae. Intellectual deficiency is mild to moderate. A small subset of patients, about 10 to 15 percent of cases, present with severe brain/facial malformations evocative of holoprosencephaly spectrum disorders.
Etiology
In two-thirds of the cases, the 18p- syndrome is due to a mere terminal deletion occurring de novo. In the remaining cases the following are possible: a de novo translocation with loss of 18p, missegregation of a parental translocation or inversion, or a ring chr18. Parental transmission of the 18p- syndrome has been reported.
Diagnostic methods
Cytogenetic analysis is necessary to make a definite diagnosis.
Differential diagnosis
Differential diagnosis may include a wide number of syndromes with short stature and mild intellectual deficiency. In young children, deletion 18p syndrome may be vaguely evocative of either Turner syndrome or trisomy 21 (see these terms).
Antenatal diagnosis
Deletion 18p can be detected prenatally by amniocentesis or chorionic villus sampling and cytogenetic testing.
Genetic counseling
Recurrence risk for siblings is low for de novo deletions and translocations, but is significant if a parental rearrangement is present.
Management and treatment
No specific treatment exists but speech therapy and early educational programs may help to improve the performances of the children.
Prognosis
Except for the patients with severe brain malformations, the life expectancy does not seem significantly reduced.

                            Last update: 
                            February 2008


                            - Expert reviewer(s): 
                            Dr Catherine TURLEAU
Monosomy 18q (ORPHA:1600)
A partial deletion of the long arm of chromosome 18 characterized by highly variable phenotype, most commonly including hypotonia, developmental delay, short stature, growth hormone deficiency, hearing loss and external ear anomalies, intellectual disability, palatal defects, dysmorphic facial features, skeletal anomalies (foot deformities, tapering fingers, scoliosis) and mood disorders.
Monosomy 22 (ORPHA:96123)
A rare autosomal anomaly syndrome, with a highly variable phenotype, typically characterized by short length, joint abnormalities (e.g. dysplasia, hyperextensibility, contractures, dislocation), congenital cardiac defects, and craniofacial dysmorphism (incl. microcephaly, a high, prominent, narrow and/or hairy forehead, epicanthus, upward-slanting and/or small palpebral fissures, broad, high or depressed nasal bridge and malformed ears). Delayed motor development and intellectual disability is observed in patients not presenting early demise.
Monosomy 9p (ORPHA:261112)
Monosomy 9p is a rare chromosomal anomaly characterized by psychomotor developmental delay, facial dysmorphism (trigonocephaly, midface hypoplasia, upslanting palpebral fissures, dysplastic small ears, flat nasal bridge with anteverted nostrils and long philtrum, micrognathia, choanal atresia, short neck), single umbilical artery, omphalocele, inguinal or umbilical hernia, genital abnormalities (hypospadia, cryptorchidism), muscular hypotonia and scoliosis.
Monosomy 9q22.3 (ORPHA:77301)
Interstitial 9q22.3 microdeletion is associated with a phenotype including macrocephaly, overgrowth and trigonocephaly. Psychomotor delay, hyperactivity and distinctive facial features were also observed. It has been described in two unrelated children.
Mooren ulcer (ORPHA:519408)
A rare disorder of the anterior segment of the eye characterized by a unilateral or bilateral rapidly progressive, intractable, painful, ulcerative keratitis which initially affects the peripheral cornea and may spread circumferentially and then centrally. The destructive process involves stromal corneal tissue only, leaving the epithelium and endothelium largely unaffected. There is no involvement of the adjacent sclera. The condition can be complicated by glaucoma, cataract, and perforation.
Morgagni-Stewart-Morel syndrome (ORPHA:77296)
A rare cranial malformation characterized by hyperostosis frontalis interna, variably associated with metabolic and endocrine disorders (such as obesity, diabetes mellitus, and hirsutism, among others). Compression by calvarial thickening may lead to cerebral atrophy and present with cognitive impairment, neuropsychiatric symptoms, headaches, and epilepsy. The condition predominantly affects women.
MORM syndrome (ORPHA:75858)
A rare genetic syndromic intellectual disability characterized by language delay and mild to moderate intellectual disability associated with truncal obesity, congenital nonprogressive retinal dystrophy with poor night vision and reduced visual acuity, and micropenis in males. Cataracts may occur in the second or third decade of life.
Morvan syndrome (ORPHA:83467)
Morvan syndrome is a rare, life-threatening, acquired neurologic disease characterized by neuromyotonia, dysautonomia and encephalopathy with severe insomnia. Signs involving central (e.g. hallucinations, confusion, amnesia, myoclonus), autonomic (e.g. variations in blood pressure, hyperhidrosis) and peripheral (e.g. painful cramps, myokymia) hyperactivity, as well as systemic manifestations (such as weight loss, pruritus, fever), are reported. Thymoma is present in some cases.
Mosaic genome-wide paternal uniparental disomy (ORPHA:329813)
A rare chromosomal anomaly characterized by a combination of paternal uniparental and biparental cell lineages, leading to variable clinical presentation that predominantly includes features of Beckwith-Wiedemann syndrome and increased risk of various tumors. In addition, features of Angelman syndrome and transient neonatal diabetes might be expected.
Mosaic trisomy 1 (ORPHA:1692)
A rare autosomal trisomy, characterized by reduced fetal movements and intrauterine growth retardation, low birth weight, and multiple congenital anomalies. The latter include, amongst others, facial dysmorphism (like hypertelorism, cleft lip/palate, micrognathia, low hairline, and small, low-set, and posteriorly rotated ears), head circumference below average, deformities of the hands (camptodactyly) and feet, marked hypertrichosis, and anomalies of the brain, heart, and lungs. Lethality appears to depend on the degree of mosaicism.
Mosaic trisomy 10 (ORPHA:96063)
Mosaic trisomy 10 is a rare chromosomal anomaly syndrome, with a highly variable phenotype, principally characterized by growth delay, craniofacial dysmorphism (incl. prominent forehead, hypertelorism, upslanting palpebral fissures, blepharophimosis, low-set malformed large ears, high arched palate, cleft lip/palate, retrognathia) and cardiac, renal and skeletal (e.g. radial ray defects, scoliosis) malformations, with death usually ocurring neonatally or in early infancy. Other reported features include central nervous system and ear anomalies, as well as facial clefts and anal atresia.
Mosaic trisomy 12 (ORPHA:1698)
Mosaic trisomy 12 is a rare chromosomal anomaly syndrome, with a highly variable phenotype, principally characterized by developmental or growth delay, short stature, craniofacial dysmorphism (e.g. turricephaly, tall forehead, downslanting palpebral fissures, posteriorly rotated and low set ears, narrow palate), congenital heart defects (e.g. atrial septal defect, patent ductus arteriosus), hypotonia, and pigmentary dysplasia. Scoliosis, hearing loss, facial/body asymmetry, and intellectual disability have also been reported.
Mosaic trisomy 14 (ORPHA:1703)
Mosaic trisomy 14 is a rare chromosomal anomaly disorder, with a highly variable phenotype, principally characterized by growth and developmental delay, intellectual disability, body asymmetry/hypotonia, congenital heart defects, genitourinary abnormalities (cryptorchidism, micropenis, large clitoris, labial swelling), and abnormal skin hyperpigmentation. Patients usually present with craniofacial dysmorphism such as microcephaly, abnormal palpebral fissure, hypertelorism, ear abnormalities, broad nose, low-set ears, micro/retro-gnathia, and cleft or highly arched palate.
Mosaic trisomy 15 (ORPHA:1706)
Mosaic trisomy 15 is a rare chromosomal anomaly syndrome principally characterized by intrauterine growth restriction, congenital cardiac anomalies (incl. ventricular and atrial septal defects, patent ductus arteriosus) and craniofacial dysmorphism (incl. hypertelorism, downslanting palpebral fissures, wide nasal bridge). Patients also present brain (e.g. hypoplastic cerebellum, ventricular asymmetry), renal (e.g. small dysplastic kidneys), and/or genital (undescended testis, small penis, hypoplastic labia majora) anomalies. Digital and skin pigmentation abnormalities have also been reported.
Mosaic trisomy 16 (ORPHA:1708)
Mosaic trisomy 16 is a rare chromosomal anomaly syndrome with a highly variable phenotype ranging from minor anomalies with normal development to intrauterine growth retardation, abnormal skin pigmentation, craniofacial and body asymmetry, cardiac (e.g. ventricular septal defect) and genital (e.g. hypospadias, cryptorchidism) anomalies, scoliosis and hearing loss to neonatal death. Additional features observed include skeletal malformations (e.g. clino/polydactyly, talipes), mild facial dysmorphism, and developmental delay.
Mosaic trisomy 17 (ORPHA:1711)
Mosaic trisomy 17 is a rare chromosomal anomaly syndrome, with a highly variable clinical presentation, mostly characterized by growth delay, intellectual disability, body asymmetry with leg length differentiation, scoliosis, and congenital heart anomalies (e.g. ventricular septal defect). Prenatal ultrasound findings include intrauterine growth retardation, nuchal thickening brain anomalies (e.g. cerebellar hypoplasia), pleural effusion and single umbilical artery. Patients with no associated malformations have also been reported.
Mosaic trisomy 2 (ORPHA:1723)
Mosaic trisomy 2 is a rare chromosomal anomaly syndrome, with a highly variable phenotype, principally characterized by intrauterine growth restriction, growth and motor delay, craniofacial dysmorphism (e.g. microcephaly, hypertelorism, micro/anophthalmia, midface hypoplasia, cleft lip/palate), congenital heart and neural tube defects, as well as various skeletal (e.g. scoliosis, radioulnar hypoplasia, preaxial polydactyly) and gastrointestinal (e.g. intestinal malrotation, Hirschsprung disease) anomalies. Central nervous system malformations (including ventriculomegaly, thin corpus callosum, spina bifida) have also been reported.
Mosaic trisomy 20 (ORPHA:1724)
Mosaic trisomy 20 is a rare chromosomal anomaly syndrome with a highly variable phenotype ranging from normal (in the majority of cases) to a mild, subtle phenotype principally characterized by spinal abnormalities (i.e. stenosis, vertebral fusion, and kyphosis), hypotonia, lifelong constipation, sloped shoulders, skin pigmentation abnormalities (i.e. linear and whorled nevoid hypermelanosis) and significant learning disabilities despite normal intelligence. More severe phenotypes, with patients presenting psychomotor and speech delay, mild facial dysmorphism, cardiac (i.e. ventricular septal defect, dysplastic tricuspid mitral valve) and renal anomalies (e.g. horseshoe kidneys), have also been reported.
Mosaic trisomy 22 (ORPHA:96068)
Mosaic trisomy 22 is a rare chromosomal anomaly syndrome, with a highly variable phenotype, principally characterized by prenatal and postnatal growth delay, mild to severe intellectual disability, hemiatrophy, webbed neck, ocular and cutaneous pigmentary anomalies, craniofacial dysmorphic features (e.g. microcephaly, upslanted palpebral fissures, ptosis, ear malformations, flat nasal bridge, micrognathia) and cardiac abnormalities (including ventricular and atrial septal defect, pulmonary or aortic stenosis). Hearing loss and limb malformations (e.g. cubitus valgus, syn/brachydactyly), as well as renal and genital anomalies, have also been reported.
Mosaic trisomy 3 (ORPHA:100071)
Mosaic trisomy 3 is a rare chromosomal anomaly syndrome with high phenotypic variability ranging from a mild phenotype presenting joint pain and laxity, mild facial dysmorphism (e.g. long facies, prominent eyes, dysplastic ears, downturned corners of the mouth, micrognathia) and no developmental delays to more severe phenotypes including short stature, intellectual disability, severe developmental delays, additional craniofacial dysmorphic features (e.g. brachycephaly, high forehead, flat midface, short neck) and hearing impairment, as well as skeletal (e.g. pectus excavatum, scoliosis), ocular (e.g. coloboma) and cardiac abnormalities.
Mosaic trisomy 4 (ORPHA:96059)
Mosaic Trisomy 4 is a rare autosomal anomaly, due to the presence of an extra copy of chromosome 4 in a fraction of all cells, with a variable phenotype characterized by intrauterine growth retardation, low birth weight/length/OFC, mild intellectual deficit, congenital heart defects, hypertrophic cardiomyopathy, dysmorphic features (asymmetry of the face, eyebrow anomalies, low-set, posteriorally rotated, dysplastic ears, micro-/retrognathia), characteristic thumb abnormalities (aplasia, hypoplasia) and skin abnormalities (hypo/hyperpigmentation). Delayed puberty may be associated.
Mosaic trisomy 5 (ORPHA:96060)
Mosaic trisomy 5 is a rare chromosomal anomaly syndrome with a variable phenotype ranging from clinically normal to patients presenting intrauterine growth retardation, congenital heart anomalies (mainly ventricular septal defect), multiple dysmorphic features (e.g. hypertelorism, prominent nasal bridge) and other congenital anomalies (incl. eventration of diaphragm, agenesis of corpus callosum, cloverleaf skull, clinodactyly, anteriorly placed anus). Psychomotor development may be normal in spite of low growth parameters being associated.
Mosaic trisomy 7 (ORPHA:1747)
Mosaic trisomy 7 is a rare chromosomal anomaly syndrome, with a highly variable phenotype, mostly characterized by blaschkolinear skin pigmentary dysplasia, body asymmetry, enamel dysplasia, and developmental and growth delay. Intellectual disability, facial dysmorphism (e.g. frontal bossing, abnormal palpebral fissures, strabismus, abnormally shaped ears, and micrognathia), and genital anomalies (e.g. undescended testes) have also been observed. It has been reported to be associated with maternal uniparental disomy of chromosome 7, resulting in a Silver-Russell syndrome phenotype. Cases with no associated malformations have also been reported.
Moyamoya angiopathy-short stature-facial dysmorphism-hypergonadotropic hypogonadism syndrome (ORPHA:280679)
Moyamoya angiopathy - short stature - facial dysmorphism - hypergonadotropic hypogonadism is a very rare, hereditary, neurological, dysmorphic syndrome characterized by moyamoya disease, short stature of postnatal onset, and stereotyped facial dysmorphism.
Epidemiology
The syndrome is extremely rare and has been reported in three unrelated families to date, with 10 affected individuals in several generations. These families are not from Japan or Asia, whereas in general the incidence of moyamoya disease (see this term) is highest in Japan and other Asian countries, in comparison with other parts of the world.
Clinical description
Affected patients are all male (X-linked inheritance) and have moyamoya angiopathy (progressive stenosis of the terminal portion of the intracranial internal carotid arteries), short stature, hypergonadotropic hypogonadism, and other variable manifestations including stroke, hypertension, dilated cardiomyopathy (see this term), premature coronary heart disease, premature hair graying, azoospermia, and early bilateral acquired cataract. Moyamoya angiopathy causes cerebral infarcts or hemorrhage and acute neurological symptoms. Facial dysmorphism is characterized by hypertelorism, flared nares, long philtrum, and mild ptosis. Carrier females are not affected.
Etiology
The genetic cause appears to involve Xq28 deletions removing MTCP1/CMC4and BRCC3 (Xq28) .The specific pathophysiological mechanisms underlying this disorder remain obscure, but appear to involve alteration in DNA repair.
Genetic counseling
Reported cases are suggestive of a hereditary syndrome with an X-linked recessive pattern of inheritance.

                            Last update: 
                            April 2015


                            - Expert reviewer(s): 
                            Dr Karin KLIJN
Moyamoya disease with early-onset achalasia (ORPHA:401945)
Moyamoya disease with early-onset achalasia is an exceedingly rare autosomal recessive neurological disorder reported only in a few families so far. It is characterized by the association of early onset achalasia (manifesting in infancy) with severe intracranial angiopathy that is consistent with moyamoya angiopathy in most cases (moyamoya disease; see this term). Other variable associated manifestations include hypertension, Raynaud phenomenon, and livedo reticularis.
Moynahan syndrome (ORPHA:2574)
A rare, genetic, epilepsy syndrome characterized by congenital alopecia, early-onset epilepsy, intellectual disability and speech delay. Large stature, delayed bone development and abnormal electroencephalogram have also been associated.
MPDU1-CDG (ORPHA:79323)
A rare disorder of multiple-pathway glycosylation characterised by psychomotor delay, seizures, failure to thrive, cardiomyopathy, and ichthyosis-like cutaneous anomalies.
MPI-CDG (ORPHA:79319)
MPI-CDG is a form of congenital disorders of N-linked glycosylation, characterized by cyclic vomiting, profound hypoglycemia, failure to thrive, liver fibrosis, gastrointestinal complications (protein-losing enteropathy with hypoalbuminaemia, life-threatening intestinal bleeding of diffuse origin), and thrombotic events (protein C and S deficiency, low anti-thrombine III levels), whereas neurological development and cognitive capacity is usually normal. The clinical course is variable even within families. The disease is caused by loss of function of the gene MPI (15q24.1).
MRCS syndrome (ORPHA:263347)
MRCS syndrome is a rare, genetic retinal dystrophy disorder characterized by bilateral microcornea, rod-cone dystrophy, cataracts and posterior staphyloma, in the absence of other systemic features. Night blindness is typically the presenting manifestation and nystagmus, strabismus, astigmatism and angle closure glaucoma may be associated findings. Progressive visual acuity deterioration, due to pulverulent-like cataracts, results in poor vision ranging from no light perception to 20/400.
MT-ATP6-related mitochondrial spastic paraplegia (ORPHA:320360)
A rare complex hereditary spastic paraplegia characterized by adulthood-onset of slowly progressive, bilateral, mainly lower limb spasticity and distal weakness associated with lower limb pain, hyperreflexia, and reduced vibration sense. Axonal neuropathy is frequently observed on electromyography and nerve conduction examination.
MTHFS-related developmental delay-microcephaly-short stature-epilepsy syndrome (ORPHA:597874)
A rare, genetic, neurometabolic disease characterized by microcephaly, short stature, epilepsy, cerebral hypomyelination, severe global developmental delay, and progressive spasticity. Macrocytic anemia and hyperthermia have also been reported in association. Brain imaging reveals delayed myelination with minimal progression over time, mild cerebellar atrophy and/or thin corpus callosum.