Screening for glucose-6-phosphate dehydrogenase deficiency as a preventive measure: prevalence among 1,286,000 Greek newborn infants.

We evaluated the Greek screening program for glucose-6-phosphate dehydrogenase (G6PD) deficiency, which was incorporated into the existing national phenyketonuria (PKU) screening program to identify infants with G6PD deficiency and eliminate the induction of acute hemolytic crisis by informing the families about the extrinsic factors that G6PD-deficient patients should avoid. Between 1977 and 1989, 1,286,000 infants were screened. The fluorescent spot test was used on samples extracted from dried blood spots. Abnormal fluorescence due to G6PD deficiency (severe or partial) was found in 3.14% of the samples (1 in 22 males and 1 in 54 females). The sensitivity of the test for homozygosity and hemizygosity was 100%. In heterozygosity the test identifies only subjects who have considerably diminished enzyme activity. The test is inexpensive when added to the PKU screening program ($0.90 US per test). We believe that screening a population for G6PD deficiency is justified if the incidence of the deficiency in the population is high and the clinical manifestations serious. The fluorescent spot test is recommended because it is reliable, easy to perform, and inexpensive. The test must be performed within a fortnight from sampling, and the cards must not be exposed to high temperature or humidity.