Microvillus Inclusion Disease

What is Microvillus Inclusion Disease?

Microvillus inclusion disease is an intestinal disorder characterized by severe, watery diarrhea and an inability of the intestines to absorb nutrients. Without adequate water and nutrients, children with this condition can become dehydrated, suffer from malnutrition, and fail to grow and develop normally. 

Management is difficult and relies on total parenteral nutrition.

What are the symptoms of Microvillus Inclusion Disease? 

Microvillus inclusion disease is characterized by severe, large amounts of watery diarrhea appearing at birth or within seventy-two hours.

Symptoms of a rare late onset form may not occur until two or three months after birth. Diarrhea persists even after oral feeding is stopped and does not decrease with age. Diarrhea often worsens after feeding because of insufficient absorption (malabsorption) of necessary nutrients. 

The diarrhea often results in life-threatening complications, specifically severe dehydration and metabolic acidosis, which may cause kidney failure, requiring the infant to be hospitalized.

There may also be related weight loss, growth retardation and developmental delay.

What causes Microvillus Inclusion Disease? 

Microvillus inclusion disease is thought to be caused by a basic defect in the cells in the intestinal wall of the small intestine and colon. Some researchers believe that it is inherited as an autosomal recessive trait. The specific genetic mutation involved has not yet been identified.

How is Microvillus Inclusion Disease diagnosed?

The diagnosis of microvillus inclusion disease may be based upon electron microscopy of a tissue sample (biopsy) from the intestine of an ailing child, which depicts microscopic findings characteristic of the disorder. 

Before a biopsy is performed, other causes of dehydration and diarrhea in infants are ruled out.

What are the treatments for Microvillus Inclusion Disease?

While different medications have been tried to control the severe diarrhea associated with this condition, none of them have proven effective.

Children with microvillus inclusion disease are totally dependent on parenteral nutrition for nourishment. This, however, is not a long-term solution, as children who rely on this type of nutrition are at increased risk for malnutrition, dehydration, infections and liver complications. 

A more recent and long-term management option involves intestinal (small bowel) transplantation.

Where can I find out more about Microvillus Inclusion Disease? 

• National Organization for Rare Disorders 
• NIH