Microvillus inclusion disease, previously known as Davidson's disease, congenital microvillus atrophy and, less specifically, microvillus atrophy (note: microvillus is often misspelled as microvillous), is a rare

genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders ...

of the small intestine that is inherited in an autosomal recessive pattern. Mills SE, Carter D, Greenson JK, Oberman HA, Reuter V, Stoler MH. Sternberg's Diagnostic Surgical Pathology. 4th Ed. Lippincott Williams & Wilkins. Copyright 2004. .

Presentation

It is characterized by chronic, intractable

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...

in new-born infants, starting in the first few days of life. This results in

metabolic acidosis Metabolic acidosis is a serious electrolyte disorder characterized by an imbalance in the body's acid-base balance. Metabolic acidosis has three main root causes: increased acid production, loss of bicarbonate, and a reduced ability of the kidneys ...

and severe

dehydration In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...

. 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 Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercell ...

of the small intestine. MVID is in ost cases caused by mutations in the MYO5B gene. A minority of cases involves mutations in the STX3 gene.

Diagnosis

Prenatal screening ''

in utero ''In Utero'' is the third and final studio album by American rock band Nirvana. It was released on September 21, 1993, by DGC Records. After breaking into the mainstream with their second album, ''Nevermind'' (1991), Nirvana hired Steve Albin ...

'' is currently offered by several medical centers since the

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

(s) involved in the disease were recently discovered to be

MYO5B Myosin-Vb, a myosin V type protein, is encoded by the ''MYO5B'' gene in humans. Recent evidence suggests that Myosin-Vb is related to the creation of memories by actin-dependent trafficking of AMPA receptor containing recycling endosomes in den ...

; Diagnosis is typically made by

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a dise ...

of the small intestine.

Biopsy

The appearance of microvillous inclusion disease on light microscopy is similar to

celiac sprue Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine, where individuals develop intolerance to gluten, present in foods such as wheat, rye and barle ...

; however, it usually lacks the intraepithelial

lymphocytic A lymphocyte is a type of white blood cell (leukocyte) in the immune system of gnathostomata, most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated immunity, cell-mediated, cytotoxicity, cytotoxic innate imm ...

infiltration characteristic of celiac sprue and stains positive for carcinoembryonic antigen (CEA). The definitive diagnosis is dependent on electron microscopy.

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 Parenteral nutrition (PN) is the feeding of nutritional products to a person intravenously, bypassing the usual process of eating and digestion. The products are made by pharmaceutical compounding companies. The person receives a nutritional mi ...

or an

intestinal transplant Intestine transplantation (intestinal transplantation, or small bowel transplantation) is the surgical replacement of the small intestine for chronic and acute cases of intestinal failure. While intestinal failure can oftentimes be treated wit ...

. 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 Consanguinity ("blood relation", from Latin '' consanguinitas'') is the characteristic of having a kinship with another person (being descended from a common ancestor). Many jurisdictions have laws prohibiting people who are related by blood fr ...

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

External links

{{Medical resources , DiseasesDB = 32409 , ICD10 = P78.3 , ICD9 = , ICDO = , OMIM = 251850 , MedlinePlus = , eMedicineSubj = ped , eMedicineTopic = 461 , Orphanet = 2290 Gastrointestinal tract disorders Autosomal recessive disorders Rare diseases