About davidson's disease

What is davidson's disease?

Microvillus inclusion disease is an extremely rare inherited intestinal disorder (enteropathy) that is typically apparent within hours or days after birth. The disorder is characterized by chronic, severe, watery diarrhea and insufficient absorption (malabsorption) of necessary nutrients due to incomplete development (hypoplasia) and/or degeneration (atrophy) of certain cells of the wall of the small intestine (e.g., hypoplastic villus atrophy, defective brush-border assembly and differentiation). In infants with microvillus inclusion disease, chronic diarrhea and malabsorption may result in severe dehydration, deficiency of necessary nutrients (malnutrition), a failure to grow and gain weight at the expected rate (failure to thrive), and/or disturbance of the body's balance of acids and bases, which is essential in regulating the body's composition of bodily fluids (acidosis). Microvillus inclusion disease is inherited as an autosomal recessive genetic trait.

What are the symptoms for davidson's disease?

MVID is characterized by severe, large amounts of watery Diarrhea appearing at birth or within seventy-two hours. Symptoms of a rare late onset form may not occur until two or three months after birth. Diarrhea persists even after oral feeding is stopped and does not decrease with age. Diarrhea often worsens after feeding because of malabsorption of necessary nutrients. The Diarrhea often results in life-threatening complications, specifically severe Dehydration and metabolic acidosis, which may cause kidney failure, requiring the infant to be hospitalized. There may also be related Weight loss, growth retardation and developmental delay.

Infants affected by this disorder require total intravenous hydration and total parenteral nutrition (TPN). TPN may be associated with an increased risk of developing blockage of the liver or bile ducts preventing the normal flow of bile (cholestasis) and liver failure. Liver disease and cholestatis can also occur independent of TPN due to the genetic defect in bile duct cells.

What are the causes for davidson's disease?

MVID is caused by loss of function changes (mutations) in myosin Vb (Myo5b) gene, a molecular motor gene that is responsible for traffic of proteins into the brush border of epithelial cells. Most cases of MVID are caused by mutations in Myo5b. However, some patients with MVID with late presentation and milder disease have been reported to have mutations in syntaxin 3, a gene for a SNARE protein that is responsible for vesicle fusion with the membrane.

MVID follows an autosomal recessive pattern of inheritance. Recessive genetic disorders occur when an individual inherits a non-working gene from each parent. If an individual receives one working gene and one non-working gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the non-working gene and, therefore, have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier, like the parents, is 50% with each pregnancy. The chance for a child to receive working genes from both parents is 25%. The risk is the same for males and females.

All individuals carry a few abnormal genes. Parents who are close relatives (consanguineous) have a higher chance than unrelated parents to both carry the same abnormal gene, which increases the risk to have children with a recessive genetic disorder. MVID has been reported in consanguineous families.

What are the treatments for davidson's disease?

No effective drug treatment is available. Treatment of MVID is accomplished through intravenous feeding called total parenteral nutrition (TPN).

However, chronic TPN carries with it high risks of infection (sepsis), liver damage and other organ disorders. Therefore, the affected child must be carefully monitored by a physician.

Some children with severe disease have been treated with transplantation of a part of the small intestine.

Other treatment is symptomatic and supportive. Genetic counseling is recommended for affected individuals and their families.

What are the risk factors for davidson's disease?

Davidson’s disease or Microvillus inclusion disease is an extremely rare and life-threatening intestinal disorder, that usually shows up within a few hours or days after birth.

  • Generally, each cell in the small intestine is surrounded by tiny finger-like structures, villi, and microvilli. It will increase the surface area of the cell, thereby increasing the rate of absorption.
  • These cells in the affected children will lack microvilli, which means that the fluid or nutrients cannot be absorbed by the small intestine into the bloodstream.
  • The initial treatment for the body involved direct infusion of fluid into the bloodstream through an intravenous cannula to maintain the level of minerals and salts.
  • There are no specific curable treatments or medications for Microvillus Inclusion Disease, and cannot be treated in many children.
  • However, your healthcare professionals might suggest a supportive therapy that involves long-term maintenance with proper hydration with balanced and parenteral nutrition.
  • Moreover in some cases, a small bowel transplant will cure the condition, replacing the damaged small intestine with a donated one.
  • The option is still in its beginning stage and is offered only in certain healthcare organizations.
  • After the surgery, the children are reported to consume the food orally, adapting to a normal diet and feeding regime over time.

Osteoporosis (thinning of the bones),Cholestasis (inability to produce bile fluid),Chronic kidney disease,Cirrhosis and other liver disorders
Watery diarrhoea,Malnutrition,Dehydration,Diffculty in gaining weight,Delayed growth

Is there a cure/medications for davidson's disease?

Davidson's disease, which is currently termed Microvillus Inclusion disease, is a rare genetic disorder characterized by severe watery diarrhea and insufficient absorption of essential nutrients because of the incomplete development and/or defective surfaces of the small intestine walls.

  • The gastrointestinal tract is a complex, critical organ that is responsible for the breakdown of food, and absorption of food into the bloodstream. During the process, the broken down nutrients will pass the wall of the intestine, which has villi, small finger-like structures.
  • As an autosomal recessive disorder, the condition is caused due to the malfunction of more genes, including MYO5B and STX3.
  • For instance, a mutation in the MYO5B, gene reduces the remove the myosin Vb function. Lack of such function will affect the ability of the enterocytes to form the structures called microvilli.
  • Such disorganized enterocytes coupled with poorly formed microvilli will ultimately reduce the ability of the intestine to absorb nutrients.
  • This malabsorption of nutrients and fluids during digestion will cause recurrent diarrhea, malnutrition, and dehydration in individuals.
  • Children are more likely to develop the disease, when both parents carry a copy of the affected gene, passing down the disease to their offspring.
  • In some cases, more than one child will be affected by the condition, identified gene copies of Myosin 5b and Syntaxin 3.

Osteoporosis (thinning of the bones),Cholestasis (inability to produce bile fluid),Chronic kidney disease,Cirrhosis and other liver disorders
Watery diarrhoea,Malnutrition,Dehydration,Diffculty in gaining weight,Delayed growth

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