Microvillous inclusion disease
Encyclopedia
Microvillous inclusion disease, also known as Davidson's disease, congenital microvillous atrophy and, less specifically, microvillous atrophy, is a rare genetic disorder
of the small intestine
that is inherited in an autosomal recessive pattern.
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.
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.
infiltration characteristic of celiac sprue and stains positive for carcinoembryonic antigen
(CEA).
The definitive diagnosis is dependent on electron microscopy.
Microvillous inclusion disease is thought to be extremely rare; only, approximately, two dozen
cases have been identified in the medical literature.
One patient, a teenage female living in Arizona, suddenly began to grow microvilli after thirteen years of TPN (Total Parenteral Nutrition) and Lipid dependancy. She now enjoys a typical teenage diet and is seen regularly by her Gastroenterologist.
One patient from the UK was documented to achieve nutritional independence at age 3.
On 26 June 2009 a six year old girl diagnosed with microvillous inclusion disease became the third person in the UK to die of swine flu.
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....
of the small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
that is inherited in an autosomal recessive pattern.
Presentation
It is characterized by chronic, intractable diarrheaDiarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
in new-born infants, starting in the first few days of life.
This results in metabolic acidosis
Metabolic acidosis
In medicine, metabolic acidosis is a condition that occurs when the body produces too much acid or when the kidneys are not removing enough acid from the body. If unchecked, metabolic acidosis leads to acidemia, i.e., blood pH is low due to increased production of hydrogen by the body or the...
and severe dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
. Pregnancy and birth are usually normal.
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.Pathophysiology
It is caused by a congenital lack of apical microvilli in the epithelial cells of the small intestine.Diagnosis
Prenatal screening in uteroIn utero
In utero is a Latin term literally meaning "in the womb". In biology, the phrase describes the state of an embryo or fetus. In legal contexts, the phrase is used to refer to unborn children. Under common law, unborn children are still considered to exist for property transfer purposes.-See also:*...
is currently offered by several medical centers since the gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
(s) involved in the disease were recently discovered to be MYO5B
MYO5B
Myosin-Vb is a protein that in humans is encoded by the MYO5B gene.Recent evidence suggests that Myosin VB is related to the creation of memories.Mutations of MYO5B causes microvillous inclusion disease.-Interactions:...
; Diagnosis is typically made by biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
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 lymphocyticLymphocyte
A lymphocyte is a type of white blood cell in the vertebrate immune system.Under the microscope, lymphocytes can be divided into large lymphocytes and small lymphocytes. Large granular lymphocytes include natural killer cells...
infiltration characteristic of celiac sprue and stains positive for carcinoembryonic antigen
Carcinoembryonic antigen
Carcinoembryonic antigen is a glycoprotein involved in cell adhesion. It is normally produced during fetal development, but the production of CEA stops before birth. Therefore, it is not usually present in the blood of healthy adults, although levels are raised in heavy smokers...
(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
Genetic prevalence
Dozen
A dozen is a grouping of approximately twelve. The dozen may be one of the earliest primitive groupings, perhaps because there are approximately a dozen cycles of the moon or months in a cycle of the sun or year...
cases have been identified in the medical literature.
One patient, a teenage female living in Arizona, suddenly began to grow microvilli after thirteen years of TPN (Total Parenteral Nutrition) and Lipid dependancy. She now enjoys a typical teenage diet and is seen regularly by her Gastroenterologist.
One patient from the UK was documented to achieve nutritional independence at age 3.
On 26 June 2009 a six year old girl diagnosed with microvillous inclusion disease became the third person in the UK to die of swine flu.