Phenotypic heterogeneity in a large Thai slow-channel congenital myasthenic syndrome kinship

• Published in: Neuromuscular disorders : NMD Vol. 21; no. 3; pp. 214 - 218
• Main Authors: Witoonpanich, Rawiphan, Pulkes, Teeratorn, Dejthevaporn, Charungthai, Yodnopklao, Praphan, Witoonpanich, Pirada, Wetchaphanphesat, Suppachok, Brengman, Joan M., Engel, Andrew G.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.03.2011
• Subjects: Acetylcholine receptor; Adult; Aged; Alpha subunit; Child; Child, Preschool; Family Health; Female; Glycine - genetics; Humans; Male; Middle Aged; Mutation - genetics; Myasthenic Syndromes, Congenital - genetics; Myasthenic Syndromes, Congenital - pathology; Myasthenic Syndromes, Congenital - physiopathology; Neurology; Phenotype; Phenotypic heterogeneity; Receptors, Nicotinic - genetics; Serine - genetics; Siblings; Slow-channel congenital myasthenic syndrome; Thailand; Young Adult; Thailand; Slow-channel congenital myasthenic syndrome; Acetylcholine receptor; Phenotypic heterogeneity; Alpha subunit
• ISSN: 0960-8966; 1873-2364; 1873-2364
• DOI: 10.1016/j.nmd.2010.12.006

The slow-channel congenital myasthenic syndrome (SCCMS) is an autosomal dominant neuromuscular disorder caused by mutations in different subunits of the acetylcholine receptor (AChR). We here report our clinical findings in three generations of a large Thai kinship suffering from SCCMS and trace the disease to the p.Gly153Ser mutation in the AChR α subunit. The same mutation had previously been reported only in Caucasian but not in Asian patients. The clinical features include ptosis, ophthalmoparesis, and weakness of the cervical and finger extensor muscles as well as marked phenotypic heterogeneity.