Objective Glucose- 6- phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathic disease which causes neonatal jaundice in most cases, and in association with intake of drugs or certain foods (for example fava) can cause haemolytic crises. The aim of the study was to determine the prevalence of G6PD deficiency in Isfahan, the central state of Iran.

Methods From February to March 2006, a total of 2501 samples were screened for the quantitative measurement of G6PD activity by enzymatic colorimetric assay using a commercial kit (GAMMA, Belgium). The neonates referred from 17 delivery units to Isfahan neonatal screening center at day 3–7 of birth. Any neonate with a value less than 6.4 U/gHb was considered G6PD deficient.

Results Of the 2501 newborns (1307 males, 1194 females) screened, 79 neonates were found to have G6PD deficient (67 males, 12 females). The overall incidence of G6PD deficiency was 3.2%. Frequency in the male population was 5.1% (67 neonates of 1307 male neonates) and in the female population was 1% (12 neonates of 1194 female neonates). The female:male ratio was 1:5.5 (P = 0.0001). The mean enzyme activity in deficient patients was 3.22±1.8 U/gHb (male deficient group; 3.17±1.74 U/gHb, female deficient group; 3.49±2.17 U/gHb, P = 0.58).

Conclusions Routine neonatal screening in Isfahan, Iran with a relatively high prevalence of G6PD deficiency is justifiable because the World Health Organization recommends screening all newborns in populations with a prevalence of 3 to 5% or more in males.