What gene change causes biotinidase deficiency?
Biotinidase deficiency is caused by changes in the BTD gene. The BTD gene is responsible for making an enzyme called biotinidase. Biotinidase deficiency-related BTD gene changes lead to lower than usual (or completely absent) amounts of biotinidase activity in the body.
More Causes Content
Why is biotinidase deficiency caused by BTD gene changes?
The BTD gene is responsible for making an enzyme called biotinidase. The biotinidase enzyme is responsible for releasing a specific B vitamin known as biotin that is bound to proteins in some foods. When biotin is unbound by the biotinidase enzyme, it is known as free biotin. Free biotin is used in the body by a group of enzymes known as biotin-dependent carboxylases. Biotin-dependent carboxylases are used to break down proteins, fats, and carbohydrates from the food we eat to make them usable by the body. A lack of normal biotinidase enzyme activity leads to biotin not being appropriately unbound and biotin-dependent carboxylases cannot work properly.
Does anything make biotinidase deficiency worse?
The amount of biotinidase enzyme activity present in an individual is coded for by the BTD gene. However, individuals with biotinidase deficiency should avoid eating raw eggs. There is a specific protein found in egg whites called avidin. Avidin binds biotin and makes it unavailable to the body. Since individuals with biotinidase deficiency already have less free biotin available in their body than normal, they should avoid eating raw eggs in order to not have avidin bind up free biotin that might otherwise be available to their bodies. Cooking eggs inactivates avidin so it no longer binds biotin, and so it is fine for individuals with biotinidase deficiency to eat cooked eggs.
- Genereviews - Biotinidase Deficiency - https://www.ncbi.nlm.nih.gov/books/NBK1322/