Dihydropyrimidine dehydrogenase (DPD) deficiency is a disorder characterized by a wide range of phenotypic variability that range from no symptoms to a severe neurological involvement. A severely affected patients show epilepsy, intellectual disability, hypertonia and have microcephaly. The disease prevalence is unknown. Patients with DPD deficiency including those who do not show the signs of the disease are vulnerable to life-threatening toxic reactions to certain drugs called fluoropyrimidines that are used to treat cancer. Diagnosis can be done my measuring the level of uracil and thiamin, which are usually increased in affected patients along with genetic testing.
Moammar et al. (2010) reviewed all patients diagnosed with inborn errors of metabolism (IEM) from 1983 to 2008 at Saudi Aramco medical facilities in the Eastern province of Saudi Arabia. During the study period, 165530 Saudi infants were born, of whom a total of 248 newborns were diagnosed with 55 IEM. Affected patients were evaluated based on clinical manifestations or family history of similar illness and/or unexplained neonatal deaths. Almost all patients were born to consanguineous parents. Two cases out of 248 were diagnosed to have DPD deficiency with an estimated incidence of 1 per 100,000 live births. The authors concluded that data obtained from this study underestimate the true figures of various IEM in the region. Therefore, there is an urgent need for centralized newborn screening program that utilizes tandem mass spectrometry, and offers genetic counseling for these families.