Late-onset multiple carboxylase deficiency
Type of disease: Rare conditions
Biotindase deficiency (BIOT) is a rare genetic condition. BIOT results from a mutation (error) in the BTD gene. People with BIOT cannot reuse and recycle the vitamin, biotin. Biotin is needed to break down the fats, proteins, and carbohydrates we get from eating food. Typically, enzymes (special proteins) break down the food we eat into substances our body can use. If our body does not make enough of a working enzyme, then the substances we need from our food may not be available. In this case, there is not enough functioning or working biotinidase to free the vitamin biotin from our food. As a result, other enzymes which need biotin to work correctly cannot function.
There are two forms of BIOT. If there is less than 10% working biotindase, profound BIOT occurs and the symptoms and damage are more severe. If there is 10-30% working biotindase then partial BIOT occurs with symptoms are less severe. Signs of this condition often begin to show a few months after birth. However, in some cases they do not appear until childhood. A few symptoms include seizures, weak muscle tone, trouble breathing, skin rash, hair loss, trouble balancing, or a fungal infection called candidiasis. Treatment for this condition includes biotin supplements to help break down the fats, proteins, and carbohydrates. Lifelong treatment is needed.
BIOT is autosomal recessive. Early diagnosis has shown to be effective in improving the health of individuals with BIOT. Many babies are screened at birth so that treatment may begin early, however the conditions included in newborn screening vary state by state. For more information, visit Baby’s First Test. Talk with your doctor to determine which treatment options are best for your child. Support groups are a good source of information. A genetic counselor will help you understand the genetics.