The clinical value of fluorescence quantitative assay and G6PD/6PGD ratio method in the diagnosis of glucose-6-phosphate dehydrogenase deficiency and gene mutation / 中华检验医学杂志

ABSTRACT

Objective:To investigate the diagnostic value of fluorescence quantitative method and G6PD/6PGD ratio method in glucose-6-phosphate dehydrogenase (G6PD) deficiency and the type of gene mutation.Methods:A total of 1 201 patients (711 males and 490 females) with suspected G6PD deficiency in Shanghai Children′s Hospital were collected from June 2018 to March 2021. Fluorescence quantification method, G6PD/6PGD ratio method and multicolor melting curve were used to detects enzyme activity, ratio and gene mutation type. Comparison of each index and evaluation of its diagnostic efficiency were performed.Results:Among 1 201 suspicious samples, 163 cases (135 males and 28 females) were finally diagnosed. 156 cases were diagnosed by fluorescence quantitative method with a detection rate of 95.71%, and 140 cases were diagnosed by G6PD/6PGD ratio method with a detection rate of 85.89%. enzymatic activity of G6PD and ratio of G6PD/6PGD in male were significantly lower than female, and the differences were statistically significant ( U=642.5, 734.5, P<0.001). 112 cases received G6PD gene mutation detection and 92 cases were diagnosed, 74 were hemizygous mutations, 1 were homozygous mutations, 15 were heterozygous mutations, and 2 were compound heterozygous mutations. Among 15 cases of heterozygous mutations, 11 cases were diagnosed by fluorescence quantitative method, the diagnosed rate was 73.33%, 4 cases were diagnosed by G6PD/6PGD ratio method, and the diagnosed rate was 26.67%. A total of 7 mutation sites were detected and the proportions were c.1388G>A (32.22%), c.1376G>T (30.00%), c.871G>A (13.33%), c.1024C>T (11.11%). c.95A>G (7.78%), c.487G>A (4.44%), c.392G>T (1.11%). The enzymatic activities of c.1376G>T and c.1024C>T, c.487G>A were statistically significant ( P<0.001,0.015); the G6PD/6PGD ratios of c.1024C>T and c.1388G>A, c.1376G>T were statistically significant ( P=0.017,0.002,0.011,0.013). Fluorescence quantitative method had sensitivity of 100%, specificity of 95.65%, and the area under the curve (AUC) is 0.972. The sensitivity of the G6PD/6PGD ratio method was 100%, the specificity was 94.57%, and the AUC was 0.979. The sensitivity of fluorescence quantitative method combined with G6PD/6PGD ratio was 96.7%, the specificity was 100%, and the AUC was 0.992. Conclusions:Compared with fluorescence quantification, the G6PD/6PGD ratio method might not be able to diagnose female heterozygotes effectively; The panel of G6PD fluorescence quantification and G6PD/6PGD ratio was helpful to reduce the missed diagnosis. Combined with gene mutation analysis, it could improve the diagnosis rate of G6PD deficiency in the children.