Study of cPMP (Precusor Z) to Treat Molybdenum Cofactor Deficiency (MoCD) Type A

Inclusion Criteria: * Neonate or infant, less then 6 weeks at the time of diagnosis, age less than 8 weeks at start of treatment with the study medication. It is important to diagnose the condition and initiate treatment as soon after birth as possible. * Documented diagnosis of molybdenum cofactor deficiency (MoCD) Type A based on the absence of cPMP and the presence of sulfite and s-sulfocysteine in the urine, absence of urothione in the urine and genetic analysis showing a mutation in the MOCS1 gene * A parent or legal guardian voluntarily provided written informed consent to participate in the study and comply with study procedures. * Approval of the study protocol by the local HE / IRB and government or regulatory authorities (if applicable) Exclusion Criteria: * MoCD Type B (MOCS2 mutation) or Type C (gephyrin gene mutation) * Sulfite oxidase deficiency * Patients older than 6 weeks at the time of diagnosis