Prevalence of pediatric neuromuscular disorders in the Southwest region of France

Around the world, epidemiological data on neuromuscular disorders (NMD) in the pediatric population are very limited. Through medical and genetic hospital records in expert NMD centers (Toulouse, Montpellier, Bordeaux), from May 2001 to June 2022, NMD pediatric prevalence and the epidemiological profile of these disorders were investigated. We performed a retrospective cohort study with data from the French National Rare Disease Databank, which gathers a minimal dataset on all patients. The prevalence by diagnosis and age group or by year and survival from birth for muscular disorders by sub-group were analyzed. 1621 children were included with 62 % males. We estimated the regional prevalence at 37.9 (CI95 % = 35.3 - 40.7)/100,000 inhabitants under 18 years old. For the muscular disorder sub-cohort analysis, we estimated regional prevalence for Duchenne, Becker, Charcot-Marie-Tooth type 1 and Spinal Muscular Atrophy at 5 (CI95 % = 4.1 - 6.1), 1.3 (CI95 % = 0.9 - 1.9), 6.2 (CI95 % = 0.1 - 7.3) and 3.2 (CI95 % = 2.5 - 4.1), respectively. Our findings seem in accordance with other previous but scarce data. Together, these data may reflect a consensus across countries. This epidemiological study is the first robust estimation of the French pediatric prevalence of neuromuscular disorders and presents a strong starting point to be confirmed by analyses extended to all French expert centers.