A novel c.197T -> A variant among Brazilian neonates with glucose-6-phosphate dehydrogenase deficiency

ABSTRACT

Glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) deficiency is the most common enzyme deficiency worldwide, causing a spectrum of diseases including neonatal hyperbilirubinemia and acute or chronic hemolysis. We used the methemoglobin reduction test and G6PD electrophoresis to screen 655 neonates (354 females and 301 males) for common G6PD mutations in the city of Salvador in the Northeastern Brazilian state Bahia and found that 66 (10.1 percent) were G6PD-deficient (41 females and 25 males). The 66 (10.1 percent) G6PD-deficient neonates were assessed for the c.376 A -> G (exon 5) and c.202 G -> A (exon 4) mutations using the polymerase chain reaction and restriction enzyme fragment length polymorphism (PCR-RFLP) analysis and the results validated by DNA sequencing. Of the 66 G6PD-deficient neonates investigated we found that 54 (81.8 percent) presented the c.376 A -> G (p.Asn126Asp) and c.202 G -> A (p.Val68Met) mutations, two (3 percent) had the c.376 A -> G mutation only, two (3 percent) had the c.202 G -> A mutation only, five (7.6 percent) exhibited a previously unrecorded 197T -> A (p.Phe66Thr) substitution in exon 4 and three showed no mutations at any of these sites. Of the five neonates exhibiting the new 197T -> A (p.Phe66Thr) substitution, four (6.1 percent) also presented the c.202 G -> A and c.376 A -> G mutations and one (1.5 percent) had the c.[197T -> A / 202 G -> A] combination. We propose to name the new variant G6PD Bahia.