ABSTRACT
Glucose-6-phosphate dehydrogenase [G6PD] deficiency is a heterogeneous enzyme abnormality with a high frequency among people of African, Mediterranean and Southeast Asian origins. In almost every group studied in the Middle East, only three to four different G6PD mutations were detected. Among these, the G6PD Mediterranean mutation [563C -> T] was by far the most common. Apart from this mutation, little is known about the genetic heterogeneity of G6PD deficiency in Egypt. To screen for G6PD gene mutations in a group of Egyptian children with G6PD-deficiency who were previously screened for the Mediterranean [563C -> T] mutation. This work was conducted on twenty-one unrelated Egyptian children [17 males and 4 females] presenting with G6PD deficiency previously screened for the G6PD Mediterranean mutation [563C -> T]. Carefully-preserved DNA of patients refrigerated at -20°C and DNA of 21 age-matched normal subjects extracted from blood leukocytes by saltingout technique were screened for mutations in the G6PD gene by PCR-single strand conformation polymorphism [SSCP] analysis followed by DNA sequencing. In addition to the G6PD Mediterranean mutation 563C -> T previously identified by PCR-RFLP analysis in 6/21 male patients [28.6%], a further of 2 different mutations; G6PD A- mutation and G6PD Chatham were observed in 2/21 [9.5%] and 1/21 [4.8%] patients respectively. Twelve patients [57.1%] remained uncharacterized at the genetic level, a normal African G6PD A genotype was detected in one patient of them. Patients with G6PD Mediterranean mutation were more susceptible to hemolysis than were patients with G6PD A- and G6PD Chatham mutations. The lower prevalence of G6PD Mediterranean mutation in our patients and the finding of three different mutations in a relatively small number of G6PD-deficient subjects reflect the considerable genetic heterogeneity of G6PD deficiency of the Egyptian population