Overview
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.
Description
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.
Eligibility
Inclusion Criteria:
- CDM group:
- Age neonate to 3 years 11 months at enrollment.
- A diagnosis of CDM, which is defined as children having symptoms of myotonic dystrophy in the newborn period (<30 days), such as hypotonia, feeding or respiratory difficulty, requiring hospitalization to a ward or to the neonatal intensive care unit for more than 72 hours; and a genetic test confirming an expanded trinucleotide (CTG) repeat in the DMPK gene in the child or mother. An expanded CTG repeat size in the child is considered greater than 200 repeats or E1-E4 classification (E1= 200-500, E2=500-1,000, E3=1,000-1,500, E4>1,500).
- Guardian is willing and able to sign consent and follow study procedures
- ChDM Group:
- Age 1 to 4 years 11 months at enrollment.
- A diagnosis of ChDM, which is defined as symptoms associated with DM1, absence of symptoms at birth, and a genetic test confirming an expanded trinucleotide (CTG) repeat in the DMPK gene in the child or mother.12 An expanded CTG repeat size in the child is considered greater than 200 repeats or E1-E4 classification (E1= 200-500, E2=500-1,000, E3=1,000-1,500, E4>1,500).
- Guardian willing and able to sign consent and follow study procedures
Exclusion Criteria: (Both groups)
- Any other non-DM1 illness that would interfere with the ability or results of the study in the opinion of the site investigator
- Significant trauma within one month
- Internal metal or devices (exclusion for DEXA component)
- History of bleeding disorder or platelet count <50,000
- History of reaction to local anesthetic