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 of the

small intestine The small intestine or small bowel is an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through the p ...

that is inherited in an

autosomal recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

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 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. Pregnancy and birth are usually normal.

Pathophysiology

It is caused by a congenital villus atrophy, atrophy of apical

microvilli Microvilli (singular: microvillus) are microscopic cellular membrane protrusions that increase the surface area for diffusion and minimize any increase in volume, and are involved in a wide variety of functions, including absorption, secretion, ...

and intracellular accumulation of apical enzymes and transporters in the epithelial cells 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'' 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 Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...

is similar to celiac sprue; however, it usually lacks the intraepithelial lymphocytic infiltration characteristic of celiac sprue and stains positive for

carcinoembryonic antigen Carcinoembryonic antigen (CEA) describes a set of highly related glycoproteins involved in cell adhesion. CEA is normally produced in gastrointestinal tissue during fetal development, but the production stops before birth. Consequently, CEA is ...

(CEA). The definitive diagnosis is dependent on

electron microscopy An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi ...

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

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