Bowel "dissection" in microvillus inclusion disease

Area of Science:

• Gastroenterology
• Genetics
• Pediatric Pathology

Background:

• Microvillus inclusion disease (MVID) is a rare congenital enteropathy characterized by ultrastructural abnormalities of the small intestinal epithelium.
• Mutations in the MYO5B gene are a known cause of MVID, leading to impaired apical trafficking and epithelial barrier function.
• Infants with MVID typically present with severe diarrhea and failure to thrive, often requiring long-term parenteral nutrition.

Observation:

• This report details a preterm male neonate diagnosed with MVID, confirmed by histological, ultrastructural, and MYO5B mutation analysis.
• At 5 months of age, the infant unexpectedly passed a segment of bowel in his diaper.
• Serial abdominal ultrasounds revealed progressive dissection of the bowel wall with detached mucosa, a novel observation in MVID.

Findings:

• Histological examination of the detached bowel segment confirmed the presence of small intestinal epithelia.
• Postmortem autopsy revealed diffuse detachment of the small bowel mucosa without evidence of perforation.
• This represents the first documented case of MVID presenting with spontaneous bowel dissection.

Implications:

• The findings suggest that MYO5B mutations can lead to severe disruption of intestinal epithelial adhesion and integrity, potentially causing gastrointestinal tract epithelial detachment.
• This unique presentation expands the clinical spectrum of MVID and underscores the critical role of the epithelial barrier in intestinal health.
• Further research into the pathomechanisms of MYO5B mutations in MVID may reveal new therapeutic targets for intestinal epithelial disorders.