Microvillus Inclusion Disease (MVID) is a rare congenital intestinal disorder that primarily affects newborns. MVID manifests in the first hours or days of life with chronic watery diarrhea that increases in frequency with food intake, causing malnutrition and dehydration. Fewer than 100 cases have been documented.

MVID is caused by a mutation in the Myo5b gene and follows an autosomal recessive inheritance pattern. The Myo5b gene regulates proteins in the epithelial lining of the intestines. In infants with MVID, this gene is non-functional; as a result, intestinal microvilli, structures which aid in the absorption of nutrients, are deformed or entirely absent.

Diagnostic testing: A diagnosis of MVID can be confirmed through electronic microscope observation of an intestinal tissue sample, or through genetic testing. Other conditions such as lactose intolerance and familial chloride diarrhea must be ruled out before performing a biopsy.

Physical findings: Symptoms of MVID include:

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  Chronic, watery stool;

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  Dehydration;

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  Abdominal bloating;

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  Itching; and

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  Developmental delay.

ICD-9: 751.5

ICD-10: P78.3; Q43.8

MVID typically leads to developmental delay, failure to thrive, irreversible damage to the liver and kidneys, and often results in death in infancy. Most children with MVID do not survive past early childhood.

There is no cure for MVID. Parenteral (intravenous) nutrition is the most common form of treatment, but it is not a viable long-term option due to risk of infection and organ damage.

Intestine transplantation has more favorable outcomes. However, donor organs are not widely available and lifelong treatment is necessary even with a successful transplant.

Other treatment is symptomatic and supportive.

Suggested MER for Evaluation:

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  Clinical history and examination that describes the diagnostic features of the impairment;

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  Electron microscopic analysis of intestinal tissue sample; and

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  Results of molecular genetic testing for mutation of Myo5b.

Suggested Listings for Evaluation:

REMARKS

Requirement for parenteral feeding equals listing.

Small intestine transplantation, if performed, equals listing.