Media type: E-Article Title: Neuromotor synapses in Escobar syndrome Contributor: Robinson, Karyn G.; Viereck, Matthew J.; Margiotta, Megan V.; Gripp, Karen W.; Abdul‐Rahman, Omar A.; Akins, Robert E. Published: Wiley, 2013 Published in: American Journal of Medical Genetics Part A, 161 (2013) 12, Seite 3042-3048 Language: English DOI: 10.1002/ajmg.a.36154 ISSN: 1552-4825; 1552-4833 Keywords: Genetics (clinical) ; Genetics Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:sec><jats:label /><jats:p>The Escobar variant of multiple pterygium syndrome (OMIM #265000) is a rare, autosomal recessive disorder associated with mutations in the γ‐subunit of the nicotinic acetylcholine receptor (<jats:italic>CHRNG</jats:italic>). <jats:italic>CHRNG</jats:italic> is expressed in fetal muscle during motor development and contributes to the formation of neuromuscular junctions (NMJs). Anomalies in NMJ structure and function have not been investigated in patients with Escobar syndrome. We report five patients identified as having Escobar syndrome, from four families. In three families, the same mutation (c.459dupA) was identified in <jats:italic>CHRNG</jats:italic>. A biopsy from brachioradialis muscle was collected from a patient from one of these families and analyzed for NMJ organization using fluorescence microscopy. Compared to spinalis muscle from control patients with idiopathic scoliosis or cerebral palsy (CP), the patient with Escobar syndrome had a significantly higher degree of acetylcholine receptor present outside acetylcholinesterase and significantly less acetylcholinesterase outside acetylcholine receptors. Given the role of the acetylcholine receptor γ‐subunit in fetal neuromuscular signal transduction and in establishing the primary encounter of muscle and motor nerve terminal, the <jats:italic>CHRNG</jats:italic> mutations described in Escobar syndrome may cause a broader disruption of postsynaptic proteins and result in aberrant development of the NMJ due to impaired prenatal neuromuscular transmission and/or abnormal neuromuscular synaptogenesis. © 2013 Wiley Periodicals, Inc.</jats:p></jats:sec>