Gene mutation analysis of glucose-6-phosphate dehydrogenase deficiency among infants in Kunming / 中华检验医学杂志

ABSTRACT

Objective:To analyze the genetic mutation characteristics of glucose-6-phosphate dehydrogenase (G6PD) deficiency among infants in Kunming.Methods:A total of 15 533 infants (7 994 males and 7 539 females) born in Kunming from January 1, 2018, to December 31, 2020, with an age range of 2 to 44 days, were selected. G6PD enzyme activity and gene mutation types were detected using fluorescence quantitative analysis, multicolor melting curve analysis (MMCA), and Sanger sequencing. Droplet digital PCR (ddPCR) was used for quantitative analysis of a newly identified variant family to determine the mutant allele proportion in family members. Meanwhile,the protein structure model and pathogenicity prediction of the novel variant were analyzed.Data analysis was conducted using SPSS 26.0. Specifically, chi-square tests were used for the detection rates of G6PD enzyme activity and gene mutations between different genders. One-way analysis of variance (ANOVA) was used for the comparison of enzyme activity among different mutation types.Results:Among 15 533 infants, 143 cases (129 males and 14 females) were tested positive for G6PD activity, with a detection rate of 0.92% (143/15 533). The difference in detection rates between males and females was statistically significant (χ 2=96.76, P<0.001). Out of 89 enzyme activity-positive cases (83 males and 6 females) underwent genetic testing, 77 (72 males and 5 females) were detected by MMCAand other 12 negative samples were underwent further Sanger sequencing, revealing mutations in 6 samples, all of which were males. Among the 83 individuals with gene mutations, 78 had heterozygous mutations, 1 had a homozygous mutation, and 4 had compound heterozygous mutations. A total of 12 mutation types were detected, with G6PD c.487G>A, c.1024C>T, c.1388G>A, and c.1376G>T being the most common, accounting for 74.70% (62/83) of all mutation types. The average G6PD enzyme activity of c.1376G>T was the lowest, and the differences were statistically significant compared to the average enzyme activity of the other three mutations ( P<0.05). One male infant with a newly identified G6PD c.242G>C mutation was detected, predicted to be pathogenic. ddPCR confirmed that the mother of the affected child was a c.242G>C mutant chimera, with a chimera proportion of 6.66%. Conclusions:In the Kunming region, the predominant G6PD deficiency gene mutation is c.487G>A, with the detection of a novel G6PD c.242G>C mutation. The application of ddPCR technology can assist in detecting the proportion of mutation chimeras.