MOLECULAR CHARACTERIZATION OF GLUCOSE-6-PHOSPHATE-DEHYDROGENASE DEFICIENCY IN CHINESE INFANTS WITH OR WITHOUT SEVERE NEONATAL HYPERBILIRUBINEMIA

To characterize mutations in the glucose-6-phosphate dehydrogenase (G6 PD) gene in Chinese infants, we studied 213 G6PD-deficient infants wit hout blood exchange transfusion (BET) therapy, and 34 patients who req uired BET therapy for their severe hyperbilirubinaemia after birth. Ni ne different point mutations were characterized in all infants. Of the se mutations, the G to T substitution at cDNA nucleotide (nt) 1376, wh ich 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 substitutio n 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, a nd G to T substitution at nt 399 in three (1.2%) infants, G to A subst itution at nt 487 in two (0.8%) infants, C to T substitution at nt 136 0 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 cha racterized. Most (64.7%) mutations in the G6PD-deficient infants who r equired BET therapy after birth result from a G to T substitution at n t 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 jau ndice requiring BET therapy can take place with the majority of varian ts encountered in this area.