Molybdenum Cofactor Deficiency: Mega Cisterna Magna in Two Consecutive Pregnancies and Review of the Literature

The molybdenum cofactor deficiency is an autosomal recessive disease, characterized by rapidly progressive and severe neurological damage that mimics a hypoxic-ischemic encephalopathy due to the accumulation of toxic metabolites that cause rapid neurodegeneration after the delivery. It is eventually lethal, in a similar way to the rare isolated sulfite oxidase deficiency. This serious pathology usually causes death in the immediate neonatal period in the more severe variants. We report a case of two consecutive pregnancies with enlarged cisterna magna as the only prenatal pathological finding since 26 weeks of gestation (WG) and the subsequent death of the newborns in the first week after birth. After the second pregnancy, we reached the diagnosis of molybdenum cofactor deficiency due to MOCS1 gene mutation. According to the cases reported in the literature, this is the case with the earliest neuroimage prenatal findings.