Lipoic Acid Biosynthesis Defects
Lipoic acid biosynthesis defects are a group of conditions caused by different enzymatic deficiencies. Lipoate is a cofactor essential for important reactions in humans involving several genes (LIPT1, LIAS, DLD) which codifiy different enzymes. Mutations in LIAS have been identified that result in a variant form of nonketotic hyperglycinemia with early-onset convulsions combined with a defect in mitochondrial energy metabolism with encephalopathy and cardiomyopathy (increased size of the heart muscle). LIPT1 deficiency resulted in early death in one patient and in a less severely affected individual with a Leigh-like syndrome clinical features. In DLD gene deficiency the clinical features are very varied depending on which of the affected enzymes is most rate limiting.