Disease:Defects in CHRNG are a cause of Escobar syndrome [MIM:265000]; also called Escobar variant multiple pterygium syndrome or nonlethal type multiple pterygium syndrome. Escobar syndrome is a nonlethal form of arthrogryposis multiplex congenita. It is an autosomal recessive condition characterized by excessive webbing (pterygia), congenital contractures (arthrogryposis), and scoliosis. Variable other features include intrauterine death, congenital respiratory distress, short stature, faciocranial dysmorphism, ptosis, low-set ears, arachnodactyly and cryptorchism in males. Congenital contractures are common and may be caused by reduced fetal movements at sensitive times of development. Possible causes of decreased fetal mobility include space constraints such as oligohydramnion, drugs, metabolic conditions or neuromuscular disorders including myasthenia gravis.,Disease:Defects in CHRNG are a cause of lethal type multiple pterygium syndrome [MIM:253290]. Multiple pterygia are found infrequently in children with arthrogryposis and in fetuses with fetal akinesia syndrome. Inheritance can be autosomal dominant, autosomal recessive, or X linked, but autosomal recessive inheritance appears to be most common. Clinical expression is very variable, and, in the severest form, lethal multiple pterygium syndrome there is intrauterine growth retardation, multiple pterygia (e.g., chin to sternum, cervical, axillary, humero-ulnar, crural, popliteal, and ankles), and flexion contractures causing severe arthrogryposis and fetal akinesia. Subcutaneous edema can be severe, causing fetal hydrops with cystic hygroma and lung hypoplasia. Oligohydramnios and facial anomalies-in particular, cleft palate-are frequent.,Function:After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane.,similarity:Belongs to the ligand-gated ionic channel (TC 1.A.9) family.,subunit:Pentamer of two alpha chains, and one each of the beta, delta, and gamma (in immature muscle) or epsilon (in mature muscle) chains.,
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