Molybdenum cofactor deficiency (MCD)

Molybdenum cofactor deficiency (MCD or MOCD) is a very rare, lethal, genetic condition caused by a loss of function of molybdenum-dependent enzymes, manifesting as severe and rapid neurological deterioration. On imaging it mimics hypoxic-ischemic encephalopathy.

Epidemiology

Less than 150 reports of this condition are found in the medical literature . It is inherited in an autosomal recessive fashion . On average, diagnosis is made by one year, and only ~50% of the published cases survived 36 months .

Clinical presentation

It usually presents within a few days of birth, typically with seizures, motor neurological deficits, microcephaly, and developmental delay.

Pathology

Molybdenum is an essential trace element, forming part of a molybdenum cofactor, which is vital for the normal functioning of several enzymes, including sulfite oxidase and xanthine dehydrogenase. In molybdenum cofactor deficiency, the activity of these enzymes is reduced. The genes MOCS1, MOCS2, MOCS3, and GEPH encode critical components for the synthesis of molybdenum cofactor, and it is mutation of these genes that leads to the condition, most commonly MOCS1.

As a result there is a steep elevation in intracerebral sulfites with deleterious consequences for cellular metabolism and secondary toxic neurological sequelae.

Radiographic features

The features on MRI are very similar to those of hypoxic-ischemic encephalopathy .

History and etymology

First description of this disease was in 1978 .