[Intestinal myopathy in Steinert's disease]

Area of Science:

• Pediatric Gastroenterology
• Neuromuscular Disorders
• Gastrointestinal Motility

Background:

• Myotonic dystrophy (Steinert's disease) is a congenital, autosomal dominant disorder primarily affecting striated muscle.
• While systemic effects are known, intestinal smooth muscle involvement is less common, particularly in early childhood.

Observation:

• A 4-year-old girl diagnosed with myotonic dystrophy at birth presented with severe constipation.
• Ano-rectal manometry revealed paradoxical external sphincter activity, and rectal biopsy showed myopathy of the muscularis propria with intact innervation.
• Motility disorder was localized to the distal left colon.

Findings:

• Surgical intervention with colostomy was successful, followed by successful colon reanastomosis.
• Partial external sphincter incontinence persisted, attributed to Steinert's disease.
• The case demonstrates a pathological association of striated and smooth muscle myopathy at a very early age.

Implications:

• This case contributes to understanding intestinal pseudo-obstruction in early-onset myotonic dystrophy.
• Highlights the importance of considering smooth muscle involvement in pediatric neuromuscular disorders.
• Suggests potential for novel therapeutic strategies targeting smooth muscle dysfunction in myotonic dystrophy.