Molybdenum Cofactor Deficiency A (MOCS1)

Molybdenum cofactor deficiency A is an autosomal recessive disorder caused by pathogenic variants in the gene MOCS1. The onset of this condition occurs shortly after birth with failure to thrive, difficulty feeding, and uncontrollable seizures. Neurological abnormalities include severe developmental delay, inability to sit unassisted, and lack of speech or language development. Microcephaly, hyperekplexia (an exaggerated startle response), and coarse facial features may be present. Due to the severity of symptoms, most individuals do not live past childhood. No clear genotype-phenotype correlation has been established.

For information about carrier frequency and residual risk, please see the residual risk table.

This gene is included on the following panel(s):