Isovaleric Acidemia

Gene : IVD

What is Isovaleric Acidemia?

Isovaleric acidemia is an inherited disorder in which the body cannot properly process a particular amino acid called leucine due to defects in the enzyme isovaleryl-CoA dehydrogenase (IVD). One unique sign of isovaleric acidemia is a sweaty-foot odor coming from the body of an affected person. The more severe form has an onset within the first few days of life with symptoms that include poor feeding, vomiting, weakness, which eventually progress to seizures, coma and possibly death. Some individuals with isovaleric acidemia don't show symptoms until one year of age or later in childhood. Symptoms come and go, a situation referred to as a metabolic crisis, brought about by illness, infection, periods of fasting or eating large amounts of protein. If not carefully controlled, repeated episodes of these metabolic crises can cause brain damage, resulting in mild to moderate intellectual disability.The child may appear to be normal between these episodes, although they may have poor growth or muscle weakness. Long-term outcome can be excellent if appropriately managed with a special diet and medication. Isovaleric acidemia is caused by pathogenic variants in the IVD gene.

How is isovaleric acidemia inherited?

Isovaleric acidemia is inherited in autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant in the gene for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

What does it mean to be a carrier?

There are generally no signs or symptoms associated with being a carrier for isovaleric acidemia. However, the risk to have a child affected with isovaleric acidemia is increased. Testing of reproductive partners is recommended for carriers of isovaleric acidemia.

How common is isovaleric acidemia?

Isovaleric acidemia is a rare metabolic syndrome and is estimated to affect 1 in 250,000 newborns in the United States.

Family References and Resources
Clinician References
What is Analyzed?
  • Full gene sequencing
Affected Systems



Carrier Rates
Detection Rate
Carrier Frequency
General Population 97% 1 in 250

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