Biotinidase deficiency
Overview
What is biotinidase deficiency?
Biotinidase deficiency is a genetic, treatable, metabolic condition that is caused by the levels of an enzyme called biotinidase being too low or absent in an affected individual. Having less biotinidase enzyme activity than needed causes the body to not be able to use the vitamin biotin (sometimes referred to as vitamin H) appropriately by the body. Biotin is used by the body to assist in the break down of proteins, fats and carbohydrates from the food we eat to make them usable by the body. When biotinidase enzyme activity is too low, there is not enough biotin available in the body for proper metabolism of the food we eat.
Biotinidase deficiency is classified as partial or profound, based on how much biotinidase enzyme activity is present in the body. Individuals with untreated biotinidase deficiency may develop problems such as hypotonia (low muscle tone), eczema (skin rash), alopecia (hair loss), seizures, developmental delay, breathing problems, ataxia (balance, coordination and movement problem), candidiasis (a type of fungal infection), lactic aciduria (presence of high levels of lactic acid in the urine), hyperammonemia (higher than normal levels of ammonia in the blood), hearing loss, conjunctivitis (pink eye), lethargy (drowsiness or low energy), coma (period of unconsciousness), vomiting, diarrhea, hepatomegaly (enlarged liver), splenomegaly (enlarged spleen), speech problems and developmental delay.
Treatment of biotinidase deficiency is lifelong daily oral supplementation with free biotin. Many symptoms of untreated biotinidase deficiency are expected to improve with initiation of treatment, and since most newborns are screened for biotinidase deficiency as part of newborn screening programs, treatment is often started prior to the initiation of symptoms. Individuals with biotinidase deficiency who are appropriately treated prior to symptoms developing can be expected to remain asymptomatic.
Biotinidase deficiency is inherited in an autosomal recessive manner, and unaffected family members of affected individuals can be tested to determine their carrier status/reproductive risks for biotinidase deficiency.
References
- Genetics Home Reference - Biotinidase Deficiency - https://ghr.nlm.nih.gov/condition/biotinidase-deficiency
- Genereviews - Biotinidase Deficiency - https://www.ncbi.nlm.nih.gov/books/NBK1322/
More Overview Content
Are there other names for biotinidase deficiency?
How many people have biotinidase deficiency?
What is biotinidase deficiency called most often by doctors?
What is the usual abbreviation for biotinidase deficiency?
Are there other names for biotinidase deficiency?
Biotinidase deficiency is most often referred to as biotinidase deficiency, classified as either profound or partial. Other names for biotinidase deficiency may also include:
- BTD
- BTD deficiency
- BIOT
- Infantile multiple carboxylase deficiency
- Juvenile multiple carboxylase deficiency
- Late-onset multiple carboxylase deficiency
- Multiple carboxylase deficiency, due to biotinidase deficiency
- Late-onset biotin-responsive multiple carboxylase deficiency
References
- National Organization for Rare Disorders (NORD) - Biotinidase Deficiency - https://rarediseases.org/rare-diseases/biotinidase-deficiency/
- Baby's First Test - Biotinidase Deficiency - http://www.babysfirsttest.org/newborn-screening/conditions/biotinidase-deficiency
- Genetics Home Reference - Biotinidase Deficiency - https://ghr.nlm.nih.gov/condition/biotinidase-deficiency
How many people have biotinidase deficiency?
Approximately 1 in 60,000 babies are born with a form of biotinidase deficiency (profound or partial). More specifically, worldwide the incidence of profound biotinidase deficiency has been estimated at 1 in 137,401, partial biotinidase deficiency 1 in 109,921, and combined incidence of profound and partial biotinidase deficiency 1 in 61,067.
Biotinidase deficiency is more common in areas with a high rate of consanguinity (individuals who are blood relatives having children together, for example, first cousin marriages) such as Turkey and Saudi Arabia. The incidence of biotinidase deficiency also appears to be increased in Hispanic populations and lower in African American populations.
References
- Genetics Home Reference - Biotinidase Deficiency - https://ghr.nlm.nih.gov/condition/biotinidase-deficiency
- Genereviews - Biotinidase Deficiency - https://www.ncbi.nlm.nih.gov/books/NBK1322/
What is biotinidase deficiency called most often by doctors?
Biotinidase deficiency is most often referred to as biotinidase deficiency, but is further classified as profound biotinidase deficiency or partial biotinidase deficiency, depending on the amount of biotinidase enzyme activity present in the individual. Profound biotinidase deficiency results from less working enzyme than partial biotinidase deficiency, and is a more severe condition if untreated.
References
- Genetics Home Reference - Biotinidase Deficiency - https://ghr.nlm.nih.gov/condition/biotinidase-deficiency
What is the usual abbreviation for biotinidase deficiency?
Biotinidase deficiency may commonly be abbreviated BTD or BTD deficiency, or BIOT. BTD is also the name of the gene changed in biotinidase deficiency.
