Myotonic dystrophy type-1 (DM1) is an autosomal dominant disorder caused by a toxic CTG repeat expansion in the 3'UTR of the DMPK gene. DM1 is the most common adult-onset muscular dystrophy, with an overall prevalence of 1:8000. In approximately 10-20% of individuals with DM1, the onset of symptoms occurs at birth, which is known as congenital myotonic dystrophy (CDM). If the onset of symptoms occurs after birth and before age 10, this is known as childhood myotonic dystrophy (ChDM).~Previous studies have enrolled a very limited number of children with CDM and there is very little data to guide disease progression in ChDM.~The rationale for this study is to include a larger population of patients with CDM and ChDM, in order to determine developmental milestones, measures of physical and cognitive function and quality of life, and correlate functional outcome measures with potential biomarkers in CDM and ChDM.
The overall goal of the study is to establish valid clinical endpoint assessments for children with congenital myotonic dystrophy type 1 and childhood myotonic dystrophy type 1, and develop biomarkers for the condition.