Dysarthria, and Mandibular prognathia

Congenital myasthenic syndrome associated with AChR deficiency is a disorder of the postsynaptic neuromuscular junction (NMJ) clinically characterized by early-onset muscle weakness with variable severity. Electrophysiologic studies show low amplitude of the miniature endplate potential (MEPP) and current (MEPC) resulting from deficiency of AChR at the endplate. Patients with mutations in the CHRNE gene may have compensatory increased expression of the fetal subunit CHRNG (OMIM ) and may respond to treatment with cholinergic agents, pyridostigmine, or amifampridine (summary by Engel et al., 2015).For a discussion of genetic heterogeneity of CMS, see CMS1A (OMIM ).

MYASTHENIC SYNDROME, CONGENITAL, 4C, ASSOCIATED WITH ACETYLCHOLINE RECEPTOR DEFICIENCY; CMS4C Is also known as cms id, formerly|myasthenia, familial infantile, 1, formerly|myasthenic syndrome, congenital, type id|cms1d, formerly|fim1, formerly

• Generalized hypotonia
• Strabismus
• Muscle weakness
• Muscular hypotonia
• Ptosis

SOURCES: OMIM MENDELIAN

X-linked intellectual disability, Snyder type is a rare X-linked intellectual disability syndrome characterized by hypotonia, asthenic build with diminished muscle mass, severe generalized psychomotor delay, unsteady gait and moderate to severe intellectual disability, as well as a long, thin, asymmetrical face with prominent lower lip, long fingers and toes and nasal, dysarthric or absent speech. Bone abnormalities (e.g., osteoporosis, kyphoscoliosis, fractures, joint contractures) are also characteristic. Myoclonic, or myoclonic-like, seizures and renal abnormalities have been associated in some patients.

X-LINKED INTELLECTUAL DISABILITY, SNYDER TYPE Is also known as snyder-robinson syndrome|snyder-robinson mental retardation syndrome|srs

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: MESH ORPHANET OMIM MENDELIAN

Aniridia-cerebellar ataxia-intellectual disability syndrome, also known as Gillespie syndrome, is a rare, congenital, neurological disorder characterized by the association of partial bilateral aniridia with non-progressive cerebellar ataxia, and intellectual disability.

ANIRIDIA-CEREBELLAR ATAXIA-INTELLECTUAL DISABILITY SYNDROME Is also known as gillespie syndrome|aniridia, cerebellar ataxia, and mental retardation

• Intellectual disability
• Global developmental delay
• Generalized hypotonia
• Ataxia
• Nystagmus

SOURCES: MESH OMIM ORPHANET MENDELIAN

17p11.2 microduplication syndrome is a rare chromosomal anomaly syndrome, resulting from the partial duplication of the short arm of chromosome 17, typically characterized by hypotonia, poor feeding, failure to thrive, developmental delay (particularly cognitive and language deficits), mild-moderate intellectual deficit, and neuropsychiatric disorders (behavioral problems, anxiety, attention deficit hyperactivity disorder, autistic spectrum disorder, bipolar disorder). Structural cardiovascular anomalies (dilated aortic root, bicommissural aortic valve, atrial/ventricular and septal defects) and sleep disturbance (obstructive and central sleep apnea) are also frequently associated.

17P11.2 MICRODUPLICATION SYNDROME Is also known as potocki-lupski syndrome|trisomy 17p11.2|chromosome 17p11.2 duplication syndrome

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: ORPHANET OMIM MENDELIAN

Weaver syndrome comprises pre- and postnatal overgrowth, accelerated osseous maturation, characteristic craniofacial appearance, and developmental delay. Most cases are sporadic, although autosomal dominant inheritance has been reported. Although there is phenotypic overlap between Weaver syndrome and Sotos syndrome (OMIM ), distinguishing features of Weaver syndrome include broad forehead and face, ocular hypertelorism, prominent wide philtrum, micrognathia, deep horizontal chin groove, and deep-set nails. In addition, carpal bone development is advanced over the rest of the hand in Weaver syndrome, whereas in Sotos syndrome carpal bone development is at or behind that of the rest of the hand (summary by Basel-Vanagaite, 2010).The 'Weaver-like' syndrome reported by Stoll et al. (1985) in a mother and son may be a separate entity.Sotos syndrome (OMIM ), which shows considerable phenotypic overlap with Weaver syndrome, is caused by mutation in the NSD1 gene (OMIM ) on chromosome 5q35.

WEAVER SYNDROME; WVS Is also known as weaver-smith syndrome|wss

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Scoliosis

SOURCES: OMIM MENDELIAN

In patients with SSMED, short stature and microcephaly are apparent at birth, and there is progressive postnatal growth failure. Endocrine dysfunction, including hypergonadotropic hypogonadism, multinodular goiter, and diabetes mellitus, is present in affected adults. Progressive ataxia has been reported in some patients, with onset ranging from the second to fifth decade of life. In addition, a few patients have developed tumors, suggesting that there may be a predisposition to tumorigenesis. In contrast to syndromes involving defects in other components of the nonhomologous end-joining (NHEJ) complex (see, e.g., {606593}), no clinically overt immunodeficiency has been observed in SSMED, although laboratory analysis has revealed lymphopenia or borderline leukopenia in some patients (Murray et al., 2015; Bee et al., 2015; de Bruin et al., 2015; Guo et al., 2015).

• Global developmental delay
• Short stature
• Hearing impairment
• Microcephaly
• Ataxia

SOURCES: OMIM MENDELIAN

Cockayne syndrome is characterized by abnormal and slow growth and development that becomes evident within the first few years after birth. 'Cachectic dwarfism' describes the outward appearance of afflicted individuals. Other features include cutaneous photosensitivity, thin, dry hair, a progeroid appearance, progressive pigmentary retinopathy, sensorineural hearing loss, dental caries, and a characteristic stance in the ambulatory patient. Patients often show disproportionately long limbs with large hands and feet, and flexion contractures of joints are usual skeletal features. Knee contractures result in a 'horse-riding stance.' There is delayed neural development and severe progressive neurologic degeneration resulting in mental retardation. The mean age at death in reported cases is 12.5 years, although a few affected individuals have lived into their late teens or twenties. Remarkably, in striking contrast with xeroderma pigmentosum, patients with CS have no significant increase in skin cancer or infection (Nance and Berry, 1992).Lowry (1982) noted that there is an early-onset form of Cockayne syndrome in which patients may show abnormalities at birth and have a shorter survival. Lowry (1982) thus suggested that CS could be divided clinically into the more common type I, with classic CS symptoms that manifest within the first few years or life, and the less common type II, with more severe symptoms that manifest prenatally. Mallery et al. (1998) found no correlation between genotype and phenotype among 16 patients with CS of varying severities, and concluded that clinical differences were based on other genetic backgrounds or the intrauterine environment. Genetic Heterogeneity of Cockayne SyndromeCockayne syndrome is a genetically heterogeneous disorder, and certain types show some overlap with certain forms of xeroderma pigmentosum (XP), another disorder caused by defective DNA repair. See also Cockayne syndrome B (OMIM ), caused by mutation in the ERCC6 gene (OMIM ) on chromosome 10q11; XPG/CS (see {278780}), caused by mutation in the ERCC5 gene (OMIM ) on chromosome 13q33; XPB/CS (see {610651}), caused by mutation in the ERCC3 gene (OMIM ) on chromosome 2q21; and XPF/CS (see {278760}), caused by mutation in the ERCC4 gene (OMIM ) on chromosome 16p13.Rapin et al. (2000) reviewed the clinical, pathologic, and molecular features of Cockayne syndrome, xeroderma pigmentosum, and the XP-CS complex.

COCKAYNE SYNDROME TYPE 1 Is also known as cockayne syndrome type i

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Hearing impairment

SOURCES: ORPHANET OMIM MENDELIAN

Oculodentodigital dysplasia (ODDD) is characterized by craniofacial, neurologic, limb and ocular abnormalities.

OCULODENTODIGITAL DYSPLASIA Is also known as meyer-schwickerath syndrome|odd syndrome|oculodentoosseous dysplasia|odod|oddd syndrome

• Intellectual disability
• Seizures
• Hearing impairment
• Microcephaly
• Ataxia

SOURCES: OMIM ORPHANET MENDELIAN

Floating-Harbor syndrome is a genetic developmental disorder characterized by facial dysmorphism, short stature with delayed bone age, and expressive language delay.

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Hearing impairment

SOURCES: OMIM MESH ORPHANET MENDELIAN