Head imaging abnormalities in dihydropyrimidine dehydrogenase deficiency.

Dihydropyrimidine dehydrogenase (DPD) deficiency is a rare autosomal recessive disorder of pyrimidine metabolism. Patients may present with a wide range of neurological symptoms during the first years of life. Head imaging abnormalities have been reported only rarely and include diffuse cerebral atrophy and white-matter hyperintensity. The pathogenesis of the white-matter abnormalities is unknown, although environmental factors and altered energy metabolism may be involved. To further understanding of the spectrum of brain abnormalities associated with DPD deficiency, we report a 17-month-old girl, born to a consanguineous Pakistani couple, who had a history of encephalopathy, prolonged hypoventilation, developmental delay and failure to thrive. Head MRI showed prominent sulci and abnormal T2 prolongation in the cerebral white matter and brainstem. Thus, DPD deficiency may feature prominent brain abnormalities involving the cerebral white matter and brainstem. Anoxic stress may have contributed to the clinical presentation and brain findings in this case. In order to define more clearly the contribution of DPD deficiency to the pathogenesis of these MRI abnormalities, we recommend performing detailed analysis of urine pyrimidine metabolites in patients who have such findings.