查看更多>>摘要：目的 分析昆明地区婴幼儿葡萄糖-6-磷酸脱氢酶（G6PD）缺乏症的基因突变特点。 方法 选取2018年1月1日至2020年12月31日在昆明市出生的15 533例（男7 994例，女7 539例）婴幼儿，年龄5（4，9）d，采用荧光定量法、多色熔解曲线分析法（MMCA）和Sanger测序对葡萄糖-6-磷酸脱氢酶活性和基因突变类型进行检测。采用微滴式数字PCR技术（ddPCR）对一例新发变异家系进行定量分析，确定家系成员体细胞突变嵌合比例，同时对新发变异进行蛋白结构模型分析和致病性预测。采用SPSS 26.0统计软件进行数据分析，不同性别间G6PD酶活性和基因突变阳性检出率采用χ2检验，G6PD基因突变组间酶活性的比较采用单因素方差分析。 结果 15 533例婴幼儿中G6PD酶活性检出阳性143例（男129例，女14例），检出率为0.92%（143/15 533），男女检出率差异具有统计学意义（χ2=96.76，P<0.001）。89例酶活性阳性患儿（男83例，女6例）接受了基因检测，MMCA法检出77例（男72例，女5例），12份阴性样本进一步行Sanger测序，检出突变6份，均为男性。83例基因突变者中半合子突变78例，纯合突变1例，杂合突变4例。共检出12种突变类型，以G6PD c.487G>A、c.1024C>T、c.1388G>A和c.1376G>T 4种突变类型最为常见，占全部突变类型的74.70%（62/83）。c.1376G>T的平均酶活性最低，与另外3种突变的平均酶活性相比，差异均有统计学意义（P均<0.05）。检出一例G6PD c.242G>C新发变异男性患儿，预测为致病性变异。ddPCR证明患儿母亲为c.242G>C变异嵌合体，嵌合比例为6.66%。 结论 昆明地区G6PD缺乏症基因突变以c.487G>A为主，检出一例G6PD c.242G>C新发变异。ddPCR技术可辅助用于突变嵌合体比例检测。 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 (χ2=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.
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