Molecular characterization of glucose-6-phosphate dehydrogenase deficiency in Chinese infants with or without severe neonatal hyperbilirubinaemia.

To characterize mutations in the glucose-6-phosphate dehydrogenase (G6PD) gene in Chinese infants, we studied 213 G6PD-deficient infants without blood exchange transfusion (BET) therapy, and 34 patients who required BET therapy for their severe hyperbilirubinaemia after birth. Nine different point mutations were characterized in all infants. Of these mutations, the G to T substitution at cDNA nucleotide (nt) 1376, which accounts for the mutations in 131 (53.0%) neonates, followed by G to A substitution at nt 1388 in 18 (10.5%) infants, A to G substitution at nt 493 in 17 (6.9%) infants, A to G substitution at nt 95 in 10 (4.1%) infants, C to T substitution at nt 1024 in six (2.4%) infants, and G to T substitution at nt 392 in three (1.2%) infants, G to A substitution at nt 487 in two (0.8%) infants, C to T substitution at nt 1360 in two (0.8%) infants and C to T substitution at nt 592 in two (0.8%) infants. Mutations in 48 (19.5%) G6PD-deficient infants were not characterized. Most (64.7%) mutations in the G6PD-deficient infants who required BET therapy after birth result from a G to T substitution at nt 1376. The enzyme activity of G6PD deficient infants who required BET therapy is significantly lower than for those who did not, even in a group with the same variant (as in 1376 mutation). Severe neonatal jaundice requiring BET therapy can take place with the majority of variants encountered in this area.