Chromosome 5 and the location of Molybdenum cofactor deficiency type B(MOCODB) related MOCS2 gene.
MOLYBDENUM COFACTOR DEFICIENCY TYPE B(MOCODB) is a rare genetic metabolic disorder.

The defective MOCS2 gene disturbs the normal production of the molybdenum cofactor, which is necessary for our body’s normal metabolization of sulfite, S-sulfocysteine, and more.


Map background with silhouette of a baby and words saying, "MOCODB is known to affect approximately 1 in 100,000 to 200,000 globally."
MOCODB is known to affect approximately 1 in 100,000 to 200,000 globally. 100 to 200 cases have been reported, but it is estimated that there are actually more cases that have not been diagnosed.

The characteristic symptoms of MOCODB are present from the neonatal period.


Seven symptoms of MOCODB: Encephalopathy, microcephaly, coarse facial features, feeding difficulties, hypotonia, drug-resistant tonic and clonic seizures, elevated sulfite and diminished uric acid in the urine


The diagnosis of MOCODB is based on finding its unique characteristics from clinical evaluation, blood test, and urine test.

Genetic testing for MOSC2 gene mutation can help confirm the diagnosis. If other types of molybdenum cofactor deficiency are also suspected, genetic testing for MOSC1 and GEPH gene may also be useful.

To learn more about detailed diagnosis story of a boy with MOCODB, read Diagnosis story of a boy diagnosed with MOCODB.


A family tree showing autosomal recessive inheritance pattern of Molybdenum cofactor deficiency type b(MOCODB).
MOCODB has been found to inherit in an autosomal recessive pattern.


  1. ic-treatments-black@3x-3
  2. Currently, there is no cure for MOCODB. Some medicines are used to treat seizures.

    There was a successful case* of MOCODA(type A) treated with purified cyclic pyranopterin monophosphate(cPMP), but the method is still not in use.

Helpful community for MOCODB


  • Veldman, A, Santamaria-Araujo, JA, Sollazzo, A, Pitt, J, Gianello, R, Yaplito-lee, J. “Successful Treatment of Molybdenum Cofactor Deficiency Type A with cPMP”. Pediatrics. vol. 125. 2010. pp. e1249-e1254.

Do you want to keep up with the latest post of this series?