The clinical and genetic characteristics of 17 cases with congenital myasthenic syndrome: data from a single center (P2-8.002)

Abstract

Objective: The aim of this study to investigate the clinical and genetic features of patients with Congenital Myasthenic Syndrome (CMS) in Muscle Disease Center, Koç University Hospital, Turkey. Background: CMS is a group of hereditary disorders of impaired neuromuscular transmission characterized by fatigable muscle weakness. Design/Methods: Herein, we present the characteristics of 17 patients from 14 unrelated families. Results: The mean age (3 male, 14 female) was 18.4+13.6, the onset age ranged between the first day and the first 3 months of life in 11 cases, and 1 and 16 years in 6 patients. The most common complaints at the first 3 months were ptosis (6/11), feeding difficulty (7/11), difficulty in breathing (3/11). After the first age of life, walking late (2/6) and fatigue triggered by movement (6/6) were common. CHRNE (homozygous [c.1219+2T>G]; [c.199 G>T]; and novel [c.452_454delAGG]; heterozygous [c.1220-8+8dup and c.1327–1327delG]; [ c. .1327delG and c803-2A<G]) (5 patients): All showed mildly weakness in ocular, bulbar and limbs muscles and good response to pyridostigmine. DOK7 (homozygous [c.93_95delCTGLP+c.1120_1121insGCCTP]) (3 siblings). Mild ocular and bulbar muscle weakness, moderate limbs weakness were found and benefiting from salbutamol. GFPT1 (composite heterozygous [c.50G>A and c.408+5G>A]; homozygous [c.686-2A>G]; [c.44C>T, p.]) (3 patients) and CHAT ([c.1669G>A]) (1 patient): All were ambulatory and had good response to pyridostigmine. COLQ (homozygous [14–15 exons] deletion and c.44G>A,) (3 patients ): Two siblings worsened under pyridostigmine, and had a marked response to salbutamol. The other one benefited from 3,4-diaminopyridine. AchR epsilon subunit (combined heterozygous [L240I and C302Y]) (1 patient):, She showed respiratory distress and markedly response to pyridostigmine. AGRN (novel,homozygous [c.5387G>A and C4217 A>C]) (1 Patient). She had fatigue and worsened with pyridostigmine and had a dramatic response from salbutamol. Conclusions: In our study, similar to many studies, the most common findings were ocular and bulbar symptoms, and the most common genetic disorder was postsynaptic (65%) conduction defects. Disclosure: Dr. Yunisova has nothing to disclose. Dr. ARDUC AKCAY has nothing to disclose. Dr. Avci has nothing to disclose. The institution of Dr. Eraslan has received research support from THE SCIENTIFIC AND TECHNOLOGICAL RESEARCH COUNCIL OF TURKEY. Prof. Kayserili has received research support from TUBITAK . Prof. Kayserili has received personal compensation in the range of $500-$4,999 for serving as a Projecct PI, advisor, researccher with TUBITAK . Prof. University has nothing to disclose.