Epidemiological study of congenital myasthenic syndromes based on national electronic health database of Turkiye.

OBJECTIVE: Congenital myasthenic syndromes (CMS) represent a group of genetically heterogenous disorders characterized by defective signal transmission at the neuromuscular junction. Although global prevalence of CMS remains uncertain, regional studies have reported varying prevalence rates. This study aimed to define the incidence and prevalence of CMS in Turkiye utilizing data from the national electronic health registry. Additionally, the rate of pyridostigmine prescriptions among patients with CMS was assessed. METHODS: The study was a retrospective national cohort study, and patients with at least three G70.2 ICD-10 code entries between 1 January 2015 and 22 May 2024 were included. While calculating incidence and prevalence rates official census data from the Turkish Statistical Institute were used. RESULTS: A total of 406 patients were included in the study, with females comprising 48.8% of the cohort. The mean age at diagnosis was 20.59±21.65 years (median: 12.00, min-max: 0-86). Among the cohort, 58.6% were diagnosed before the age of 18, and 12.3% before the age of one. Pyridostigmine was prescribed at least once to 68.2% of the patients. The annual incidence of CMS ranged from 0.28 to 0.59 per million between 2016 and 2023. In 2023, the incidence and prevalence rates of CMS were calculated as 0.63 and 4.49 per million, respectively. CONCLUSION: This study represents the first comprehensive nationwide epidemiological analysis of CMS in Turkiye utilizing the national electronic health registry. The study enhances the understanding of the epidemiological landscape of CMS in the country by reporting the current incidence, prevalence, and pyridostigmine prescription rates and underscores the significance of this rare but impactful neuromuscular disorder.