Glucose-6-phosphate dehydrogenase deficiency in Kuwait, Syria, Egypt, Iran, Jordan and Lebanon.

A total of 3,501 male subjects from six Arab countries living in Kuwait were investigated for quantitative and phenotypic distribution of red cell glucose-6-phosphate dehydrogenase (G6PD). The ethnic origins of those investigated were Kuwait, Egypt, Iran, Syria, Lebanon and Jordan. The distribution of G6PD deficiency among the different ethnic groups varied widely, ranging from 1.00% for Egyptians to 11.55% for Iranians. The activity of the normal enzyme was remarkably similar, with values ranging from 6.1 +/- 0.8 to 6.5 +/- 1.1 IU/g Hb. A low frequency of the Gd(A) allele was found in two ethnic groups, Egyptians (0.019) and Iranians (0.014). Gd(A-) was present at the very low frequency of 0.006 in another two ethnic groups, Kuwaitis and Jordanians.