Combined carboxylase deficiencies are a group of rare inherited metabolic disorders that affect the functioning of enzymes responsible for the breakdown of certain amino acids, fatty acids, and other molecules in the body. These deficiencies are characterized by a reduction or absence of the activity of the biotin-dependent enzymes, which are essential for the proper metabolism of these substances.
Biotin is a vitamin that plays a crucial role in activating these enzymes, and individuals with combined carboxylase deficiencies have a defect in either the transport of biotin into cells or in the functioning of the enzymes themselves. This leads to the accumulation of toxic compounds and a disruption in the normal metabolic processes.
Symptoms of combined carboxylase deficiencies can vary depending on the specific enzyme affected and the level of enzyme activity present in affected individuals. Some common symptoms may include poor feeding, vomiting, diarrhea, lethargy, seizures, developmental delays, hypotonia (low muscle tone), and skin rashes.
Combined carboxylase deficiencies are typically diagnosed through newborn screening tests or by specialized laboratory tests that measure enzyme activity levels. Treatment involves high-dose biotin supplementation to bypass the defective enzymes and support their normal function. Additionally, dietary restrictions may be necessary to help manage the symptoms and prevent further complications.
Early diagnosis and prompt treatment are crucial in order to prevent severe neurological damage and optimize the long-term outcomes for individuals with combined carboxylase deficiencies. Genetic counseling may also be recommended to help affected families understand the inheritance pattern and their risk of having children with the disorder.
