Molybdenum Cofactor Deficiency

What is molybdenum cofactor deficiency?

Molybdenum cofactor deficiency is a rare disorder that is characterized by progressive encephalopathy, or brain dysfunction. It is estimated to impact one of every 100,000 to 200,000 births throughout the world.

What are the symptoms of molybdenum cofactor deficiency?

Symptoms are not present at birth, but they appear in about a week. Symptoms include:

Difficulty feeding
Seizures that do not go away after treatment
Atrophy of brain tissue
Severe developmental delay
Inability to speak or sit independently
Microcephaly
Coarse facial features

A portion of affected individuals also have an exaggerated startle reaction.

What causes molybdenum cofactor deficiency?

One of three genes – GPHN, MOCS1, or MOCS2 – is mutated in those with molybdenum cofactor deficiency. Each gene corresponds with its own form of the disease: MOCS1 is type A, MOCS2 is type B, and GPHN is type C. They are all inherited in an autosomal recessive pattern.

The similarity between the three genes is that they all cause an issue with molybdenum cofactor when mutated. When this molecule is unable to function properly, a number of enzymes cannot do their job and metabolize various substances. These substances are toxic to the body and accumulate, causing the characteristic symptoms.

How is molybdenum cofactor deficiency diagnosed?

Doctors are typically able to diagnose this condition based on the characteristic symptoms. Urine tests, CT scans, MRIs, are used as well, and a diagnosis is confirmed through genetic testing.