ClinVar

In a child with DPD deficiency (274270), born of consanguineous parents, Vreken et al. (1997) identified a homozygous 1-bp deletion (1897delC) in the DPYD gene, resulting in a frameshift and premature termination. At the age of 9 months the patient showed febrile convulsions, severe neuromotor retardation, and spastic tetraplegia. Cerebral MRI showed ventriculomegaly with white matter hypodensity. At the age of 6 years, thymine-uraciluria was noted and DPD deficiency was demonstrated in fibroblasts. An earlier-born child had died before her first birthday with severe neuromotor retardation and febrile convulsions. Surprisingly, the father of the patient was also completely DPD deficient, although he had no history of convulsions. The mother of the patient showed intermediate DPD activity consistent with obligate carrier status. The patient was heterozygous for this 1-bp deletion, whereas the father was thought to be homozygous. The nature of the heterozygous mutation carried by the mother and transmitted to the son was not determined.