Inborn Errors of Biotin Metabolism

The document discussed two inborn errors of biotin metabolism identified in 1987, highlighting their significant impact on human physiology. The neonatal-onset disease was linked to a defect in the enzyme holocarboxylase synthetase, while the later infantile-onset disease involved a defect in the enzyme biotinidase. Both conditions presented with notable clinical symptoms affecting the skin and hair, including alopecia totalis with a red scaly body eruption in the neonatal disease, and patchy alopecia with skin lesions similar to acrodermatitis enteropathica in biotinidase deficiency. Additionally, both disorders were associated with recurrent, life-threatening acidosis and massive ketosis.