Holocarboxylase synthetase deficiency is a disorder that affects how the body uses the vitamin biotin.
If not treated, it can cause various complications. Symptoms usually show up in the first few months of life and can include trouble eating, breathing issues, skin rash, hair loss, and lack of energy. In severe cases, it might lead to delayed development, seizures, and even coma, which can be life-threatening. Luckily, this condition can be treated with biotin supplements. If taken regularly, these supplements can prevent all the symptoms of the disease. However, if treatment starts after symptoms appear, some issues like skin problems and hair loss can improve, but there might be lasting developmental problems. Biotin supplements need to be taken throughout life, and the right dosage should be determined by a doctor to ensure effective treatment.
Holocarboxylase synthetase deficiency is caused by pathogenic (disease-causing) variants in the HLCS gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background.
Other names for this condition are biotin-(propionyl-CoA-carboxylase) ligase deficiency, early-onset biotin-responsive multiple carboxylase deficiency, and infantile multiple carboxylase deficiency.