Microvillous inclusion disease

Presentation

It is characterized by chronic, intractable diarrhea in new-born infants, starting in the first few days of life. This results in metabolic acidosis and severe dehydration. Pregnancy and birth are usually normal.

Pathophysiology

It is caused by a congenital villus atrophy, atrophy of apical microvilli and intracellular accumulation of apical enzymes and transporters in the epithelial cells of the small intestine. MVID is in most cases caused by mutations in the MYO5B gene. Other genes are also responsible of the disease: STXBP2 or Munc18-2 (also causing Familial Hemophagocytic Lymphohistiocytosis (FHL), STX3 and UNC45A.

Diagnosis

Prenatal screening in utero is currently offered by several medical centers since the gene(s) involved in the disease were recently discovered to be MYO5B; Diagnosis is typically made by biopsy of the small intestine.

Biopsy

The appearance of microvillous inclusion disease on light microscopy is similar to celiac sprue; however, it usually lacks the intraepithelial lymphocytic infiltration characteristic of celiac sprue and stains positive for carcinoembryonic antigen (CEA).

Differential diagnosis

The differential diagnosis of chronic and intractable diarrhea is:

• Intestinal epithelial dysplasia
• Syndromatic diarrhea
• Immunoinflammatory enteropathy

Prognosis

It is nearly always fatal unless, like short bowel syndrome patients, treated with parenteral nutrition or an intestinal transplant. The patient is often classified as being in "intestinal failure" and treated with the cohort of patients known as "short bowel syndrome" patients.

One patient from the UK was documented as achieving nutritional independence at age 3. On 26 June 2009, a six-year-old girl with microvillus inclusion disease became the third person in the UK to die of swine flu. This was attributed to her weakened immune system.

Prevalence

Microvillus inclusion disease is extremely rare, however, no prevalence data have been published. An estimate of a few hundred children with the disease in Europe has been made but no time frame to which this count applies is given. Countries with a higher degrees of consanguinity experience higher prevalence rates due to its autosomal recessive transmission.

History

Microvillus inclusion disease was first described in 1978 by Davidson et al. It was originally described as familial enteropathy.

References

References

1. Chehade, Mirna. (2005). "Recent Advances in Paediatrics 22". Royal Society of Medicine Press.
2. Mills SE, Carter D, Greenson JK, Oberman HA, Reuter V, Stoler MH. Sternberg's Diagnostic Surgical Pathology. 4th Ed. Lippincott Williams & Wilkins. Copyright 2004. {{ISBN. 978-0-7817-4051-7.
3. Salvatore, S.. (2007). "Nutrition Support for Infants and Children at Risk". Karger.
4. Arpin, M.. (1999). "Epithelial Morphogenesis in Development and Disease". Harwood Academic.
5. "What is Microvillous Inclusion Disease?".
6. Mueller T. (2008). "MYO5B mutations cause microvillus inclusion disease and disrupt epithelial cell polarity". Nat Genet.
7. (2011). "Functional characterization of mutations in the myosin Vb gene associated with microvillus inclusion disease.". [[JPGN.
8. (2001). "Congenital microvillous inclusion disease presenting as antenatal bowel obstruction". Ultrasound Obstet Gynecol.
9. Ruemmele FM. (2007). "Chronic enteropathy: molecular basis". Nestle Nutr Workshop Ser Pediatr Program.
10. Croft NM. (2000). "Microvillous inclusion disease: An evolving Condition". J Pediatr Gastroenterol Nutr.
11. (30 June 2009). "Swine flu girl 'had tough life'". BBC News.
12. Ruemmele, Frank M. (2006-06-26). "Microvillous inclusion disease (microvillous atrophy)". Orphanet Journal of Rare Diseases.
13. (1978). "Familial enteropathy: a syndrome of protracted diarrhea from birth, failure to thrive, and hypoplastic villus atrophy". Gastroenterology.