Holocarboxylase synthetase deficiency also called Multiple Carboxylase Deficiency, Neonatal or Early Onset Form, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder of either mutations in the BTD gene or the HLCS gene. The BTD gene encodes for biotinidase and the HLCS gene encodes for holocarboxylase synthetase. This disorder is classified as a multiple carboxylase deficiency, a group of disorders characterized by impaired activity of enzymes dependent on biotin. Symptoms of holocarboxylase synthetase deficiency typically appear within the first few months of life, and include difficulty feeding, breathing problems, a skin rash, hair loss, and lethargy. Treatment using biotin supplements if immediate and lifelong can be effective in preventing many complications and managing the disorder. However, if left untreated the disorder can lead to delayed development, seizures, and coma.

Multiple Carboxylase Deficiency, Neonatal or Early Onset Form References

Biotin Metabolism References