Congenital Myasthenic Syndromes – Case Reports

Česká verzia

Authors: M. Adamovičova ^1,2; D. Šišková ²
Authors place of work: Klinika dětského a dorostového lékařství 1. LF UK a VFN v Praze ¹; Oddělení dětské neurologie, pracoviště IPVZ, Fakultní Thomayerova nemocnice s poliklinikou, Praha ²
Published in the journal: Cesk Slov Neurol N 2010; 73/106(1): 62-67
Category: Kazuistika

Summary

Congenital myasthenic syndromes started to be recognised and categorised in the 1970s, when they were first distinguished from myasthenia gravis. They are based on a genetic disorders affecting any of the proteins taking part in neuromuscular transmission. They comprise a clinically and genetically heterogeneous group of disorders, largely of autosomal recessive mode of inheritance. Fatigable weakness of skeletal muscles, also involving ocular and bulbar muscles, often manifests as early as in neonates and infants in the form of feeding difficulties with poor suck and swallowing, weak cry, ptosis, ophthalmoplegia, hypotonia, weakness and delayed motor development. The symptoms may fluctuate: crises with life-threatening acute respiratory failure are typical of some forms. Other forms may manifest as arthrogryposis or myopathy. Rarer are mild cases with onset later in childhood or in adolescence. Patients are often misdiagnosed with congenital or metabolic myopathy, muscle dystrophy or classical myasthenia. What is usually a good response to symptomatic therapy significantly changes the prognosis of the disease. In many instances, molecular genetic diagnosis is possible and prenatal testing is available. Most common in the Czech Republic is a mutation of the epsilon subunit of the acetylcholine receptor in patients of Roma ethnic origin. However, the range of congenital myasthenic syndromes is much wider. We present an overview, illustrated by case reports of the most frequent types.

Key words:
congenital myasthenic syndromes – respiratory failure – neuromuscular transmission disorders – muscle hypotonia – muscle weakness – fatigue – ptosis – ophthalmoplegia

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