title: Congenital myasthenic syndrome due to homozygous CHRNE mutations: report of patients in Arabia.
abstract: We describe the clinical characteristics of 3 siblings from 1 family with congenital myasthenic syndrome due to homozygous mutations of the gene coding for the epsilon subunit of the acetylcholine receptor (CHRNE). Onset of symptoms occurred in the first few months of life with ptosis, restricted ocular motility, mild proximal weakness, and difficulty swallowing. Multiple hospital admissions were required due to recurrent pulmonary infections. There was no decremental conduction on repetitive nerve stimulation, but jitter was increased on single fiber electromyographic. Since early childhood, our patients have done well without pulmonary or bulbar symptoms and with partial improvement on pyridostigmine therapy. Response of ptosis to diagnostic ice pack test was striking. Although these siblings have a clinical history and examination findings typical of homozygous CHRNE mutations, the clinical presentation of congenital myasthenia subtypes is variable, and accurate genotyping is essential in choosing the appropriate treatment.
authors.affiliation: Department of Pediatrics, College of Medicine, King Saud University, Division of Neurophysiology, Department of Neuroscience, Armed Forces Hospital, Riyadh, Saudi Arabia.
authors.forename: Mustafa A
authors.initials: MA
authors.lastname: Salih
authors.forename: Darren T
authors.initials: DT
authors.lastname: Oystreck
authors.forename: Yasser H
authors.initials: YH
authors.lastname: Al-Faky
authors.forename: Mohammed
authors.initials: M
authors.lastname: Kabiraj
authors.forename: Mohamed I A
authors.initials: MI
authors.lastname: Omer
authors.forename: Elamin M
authors.initials: EM
authors.lastname: Subahi
authors.forename: David
authors.initials: D
authors.lastname: Beeson
authors.forename: Khaled K
authors.initials: KK
authors.lastname: Abu-Amero
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Bosley
mesh_terms: D000293:Adolescent; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics*; D020294:Myasthenic Syndromes, Congenital / Q000208:ethnology / Q000235:genetics*; D011729:Pyridostigmine Bromide / Q000627:therapeutic use; D011978:Receptors, Nicotinic / Q000235:genetics*; D012529:Saudi Arabia / Q000208:ethnology; D035781:Siblings; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: C504423:CHRNE protein, human; D011978:Receptors, Nicotinic; D011729:Pyridostigmine Bromide