Physical function and mobility in children with congenital myotonic dystrophy

Area of Science:

• Neurology
• Pediatrics
• Genetics

Background:

• Congenital myotonic dystrophy (CDM) is a severe form of myotonic dystrophy presenting at birth.
• Understanding the physical function and muscle mass in CDM is crucial for managing the condition and developing treatments.

Purpose of the Study:

• To evaluate the relationship between physical function, muscle mass, and age in children with CDM.
• To establish reliable assessment methods for CDM and prepare for future therapeutic trials.

Main Methods:

• Participants included 37 children with CDM and 27 healthy controls (HCs), aged 3-13 years.
• Evaluated physical function using timed functional tests (TFTs) and 2-minute walk tests (2MWTs).
• Assessed muscle mass using dual-energy X-ray absorption (DEXA) scans and myometry.

Main Results:

• Children with CDM demonstrated significant limitations in walking speed and distance compared to HCs.
• Lean arm mass correlated strongly with grip strength (r=0.91).
• Lean leg mass showed a significant correlation with 6-minute walk test performance (r=0.62).

Conclusions:

• Children with CDM experience considerable deficits in strength and mobility.
• The functional tests employed were reliable for assessing CDM.
• Lean muscle mass is a potential biomarker for evaluating physical status in CDM.