What is microvillus inclusion disease?
Microvillus inclusion disease (MVID) is a rare genetic disease of the intestine that causes severe diarrhea and an inability to absorb nutrients. It usually starts soon after birth and is one of a group of disorders termed congenital diarrheas.
In MVID, the surface of the cells that line the intestine does not develop normally. This causes these cells not to work properly to absorb fluid and nutrients coming into the intestine.
Several genes have been identified that are thought to be involved in MVID. Infants and children with this disease usually need specialized intravenous nutrition (parenteral nutrition) in order to grow normally and avoid dehydration.
How we care for microvillus inclusion disease
The Boston Children’s Hospital Division of Gastroenterology, Hepatology and Nutrition Program specializes in diagnosing and treating children with complex intestinal disorders, like microvillus inclusion disease. Our congenital enteropathy team works closely with multiple specialties, including the Home Parenteral Nutrition Program, to provide expert, family centered care for infants, children, and adolescents.
Microvillus Inclusion Disease | Symptoms & Causes
What are the symptoms of microvillus inclusion disease?
Signs of MVID usually show up within hours or days after birth. However, sometimes the symptoms show up later (around two months after birth) and are less severe.
Generally, babies have severe, watery diarrhea that doesn't go away and cannot absorb the nutrients that they eat. This can lead to other severe complications, such as life-threatening dehydration, requiring the infant to be hospitalized. There may also be related poor weight gain.
What causes microvillus inclusion disease?
MVID is inherited as an autosomal recessive genetic trait. This means that both parents must carry a copy of the affected gene in order to pass the disease on to their child. In some families, more than one child is affected. The genes that have been identified include Myosin 5b and Syntaxin 3.
Microvillus Inclusion Disease | Diagnosis & Treatments
How is microvillus inclusion disease diagnosed?
Diagnosing microvillus inclusion disease (MVID) involves a number of steps. First doctors will test to determine the kind of diarrhea involved and which nutrients cannot be absorbed.
If they suspect a congenital diarrhea, they will need to look at a sample of the tissue in the small intestine. To do this they will need to perform a procedure called an endoscopy, which uses a small flexible viewing tube to look at the intestine and obtain tiny tissue samples (biopsies).
Once they have a sample they will look at it under a microscope as well as with a special microscope (electron microscope). Using electron microscopy, doctors can detect the main features of microvillus inclusion disease, which are tiny but distinct differences in the cells of the small intestine.
In addition to these tests, doctors will perform genetic testing to see whether there are any differences in the genes known to cause MVID and other congenital diarrheas.
How is microvillus inclusion disease treated?
There are currently no drug treatments for MVID. Treatment is supportive and involves long-term maintenance of nutrition and hydration with parenteral nutrition.