[Identification of molecular variants of the enzyme glucose-6-phosphate dehydrogenase by the polymerase chain reaction technique].

BACKGROUND

An assessment of the usefulness of polymerase chain reaction (PCR) in the identification of the most frequent molecular variants of the glucose-6-phosphate dehydrogenase (G6PD) in Spain: G6PD A-, G6PD Mediterranean and G6PD Seattle through the screening of the mutations: 376 A-->G; 202 G-->A; 680 G-->T; 968 T-->C; 563 C-->T and 844 G-->C.

METHODS

Three groups of patients have been studied: 1) males (40 cases); 2) relatives from the preceding group (31 cases: 7 males and 24 females), and 3) samples classified according to their fast electrophoretic mobility as G6PD A-(17 cases). The method used has been the PCR followed by digestion with specific restriction endonucleases.

RESULTS

Group 1: 23 out of 40 samples (57%), were identified as G6PD Med563T variant (8 cases), G6PD A-376G/202A (13 cases) and G6PD Seattle844C (2 cases). Group 2: The study of relatives from 13 of the 23 identified samples allowed the study of additional 31 samples (7 males, 24 females): hemizygous G6PD Med563T (3 cases), heterozygous GdB/Gd Med563T (5 cases), hemizygous G6PD A-376G/202A (4 cases), heterozygous GdB/Gd A-376G/202A (11 cases), heterozygous GdB/Gd Seattle844C (1 case) and normal females (7 cases). Group 3: In all electrophoretically fast samples classified as G6PD A-was detected the 376 A-->G mutation (characteristic of G6PD A+). In 15 of these cases a second mutation was found at nucleotide 202 G-->A (G6PD A-376G/202A); and in two, at nucleotide 968 T-->C (G6PD A-376G/968C).

CONCLUSIONS

The PCR method is fast and simple enough to allow the identification of known G6PD deficient variant, avoiding the need of its molecular characterization, which is more cumbersome and time consuming. In addition, the PCR is a very useful tool for demonstrating the carrier condition of G6PD deficiency in females with enzyme activity within normal range.