Microvillus Inclusion Disease Awareness Day Date in the current year: September 16, 2025

Microvillus inclusion disease (MVID), also known as congenital microvillus atrophy, microvillus atrophy, or Davidson’s disease, is a rare genetic disorder that affects the small intestine. Microvilli (plural for microvillus) are microscopic protrusions on the surface of some cells that increase the surface area for enhanced absorption and secretion. Intestinal microvilli increase the absorptive surface area of the small intestine, allowing for more efficient nutrient absorption and increasing the number of digestive enzymes that break down complex nutrients into simpler compounds.

Patients with MVID do not form normal intestinal microvilli, which leads to severe malabsorption and the accumulation of digestive enzymes in the epithelial cells of the small intestine. MVID causes chronic watery diarrhea that starts within the first few days of life, leading to severe dehydration and metabolic acidosis.

MVID is a genetic condition usually caused by mutations in the MYO5B gene, though other genes may also be involved. MVID has an autosomal recessive inheritance pattern, meaning a child must inherit a mutated copy of the gene from each parent for the disease to develop. Both parents must be asymptomatic carriers. MVID is an extremely rare disease with an unknown prevalence; only a few hundred children have been diagnosed with it.

Without treatment, MVID is fatal. Currently, the only treatment options are lifelong intravenous feeding or an intestinal transplant. Some patients may require a combined intestinal-liver transplant because long-term dependence on total parenteral nutrition can lead to severe liver damage, including cholestasis and liver failure. Replacing both organs simultaneously addresses both intestinal failure and parenteral nutrition-induced liver disease.

The life expectancy for patients with MVID is significantly reduced as most affected infants develop severe complications early in life. However, survival has improved with advances in total parenteral nutrition and small bowel or combined liver–intestinal transplantation. Long-term outcomes largely depend on access to these treatments and management of associated complications.

Microvillus Inclusion Disease Awareness Day isn’t an international or even a nationwide observance. September 16 was designated as MVID Awareness Day in New York State by a resolution introduced by Assemblyman Ed Ra. Ra was inspired to establish the day by Tom and Melissa Onorato, who founded the TKO Strong Foundation after their son, Thomas, was diagnosed with MVID.

The TKO Strong Foundation and Microvillus Inclusion Disease Awareness Day aim to raise awareness of this rare disease, support affected families, and raise funds for research to find a cure or more effective treatments that will improve quality of life and long-term outcomes.