Analysis of Glucose-6-Phosphate Dehydrogenase Genetic Polymorphism in the Hakka Population in Southern China

Characteristics of glucose-6-phosphate dehydrogenase mutations in newborns with deficiency from 2021 to 2022 in the Heze area of China

Introduction

Glucose-6-phosphate dehydrogenase (G6PD) deficiency has a distinct regional and ethnic heterogeneity in distribution, and information on the molecular characteristics of G6PD deficiencies in the Heze area, Shandong Province, China, is limited. We aimed to explore the incidence and genetic mutations characteristic of G6PD enzyme deficiencies in newborns in the Heze area to investigate the pathogenicity of new G6PD mutations.

Methods

We measured G6PD activity in 114,285 neonates born in the Heze area and identified 80 patients with G6PD deficiencies. The genetic mutations in G6PD in these patients were analyzed using Sanger sequencing. Functional studies were conducted by constructing eukaryotic expression vectors, transfecting them into HEK-293T and HELA cells, and measuring the mRNA and protein levels and G6PD enzymatic activity.

Results

The incidence of G6PD deficiency in the study population was 0.07% (80/114,285). We identified 17 mutation types with a 100% G6PD mutation detection rate, with four of them being significant: c.479G>A, c.404A>T, and c.486-7C>G being globally novel mutations, while c.682G>A has never been reported in China before. Functional studies revealed that the heterozygous missense mutations c.479G>A/p.S160N and c.404A>T/p.N135I increased mRNA levels, decreased protein expression, and reduced G6PD activity.

Discussion

The incidence of neonatal G6PD deficiency in the Heze area is low, and the most commonly mutated loci were c.1388G>A, c.487G>A, and c.1376G>T. Among these mutations, c.479G>A/p.S160N, and c.404A>T/p.N135I are potentially pathogenic. These mutations may cause G6PD deficiency via different mechanisms, thereby requiring further experimental investigation.

Massively parallel sequencing uncovered disease-associated variant spectra of glucose-6-phosphate dehydrogenase deficiency, phenylketonuria and galactosemia in Vietnamese pregnant women

BACKGROUND

Several inherited metabolic diseases are underreported in Vietnam, namely glucose-6-phosphate dehydrogenase deficiency (G6PDd), phenylketonuria (PKU) and galactosemia (GAL). Whilst massively parallel sequencing (MPS) allows researchers to screen several loci simultaneously for pathogenic variants, no screening programme uses MPS to uncover the variant spectra of these diseases in the Vietnamese population.

METHODS

Pregnant women (mean age of 32) from across Vietnam attending routine prenatal health checks agreed to participate and had their blood drawn. MPS was used to detect variants in their G6PD, PAH and GALT genes.

RESULTS

Of 3259 women screened across Vietnam, 450 (13.8%) carried disease-associated variants for G6PD, PAH and GALT. The prevalence of carriers was 8.9% (291 of 3259) in G6PD and 4.6% (152 of 3259) in PKU, whilst GAL was low at 0.2% (7 of 3259). Two GALT variants, c.593 T > C and c.1034C > A, have rarely been reported.

CONCLUSION

This study highlights the need for routine carrier screening, where women give blood whilst receiving routine prenatal care, in Vietnam. The use of MPS is suitable for screening multiple variants, allowing for identifying rare pathogenic variants. The data from our study will inform policymakers in constructing cost-effective genetic metabolic carrier screening programmes.

Simultaneous detection of G6PD mutations using SNPscan in a multiethnic minority area of Southwestern China

Objectives: Baise, a multiethnic inhabited area of southwestern China, is a historical malaria-endemic area with a high prevalence of G6PD deficiency. However, few studies of G6PD deficiency have been conducted in this region. Therefore, we performed a genetic analysis of G6PD deficiency in the Baise population from January 2020 to June 2021. Methods: A SNPscan assay was developed to simultaneously detect 33 common Chinese G6PD mutations. 30 G6PD-deficient samples were used for the method's validation. Then, a total of 709 suspected G6PD-deficient samples collated from the Baise population were evaluated for G6PD status, type of mutation and effect of mutations. Results: The SNPscan test had a sensitivity of 100% [95% confidence interval (CI): 94.87%-100%] and a specificity of 100% (95% CI: 87.66%-100%) for identifying G6PD mutations. A total of fifteen mutations were identified from 76.72% (544/709) of the samples. The most common mutation was discovered to be G6PD Kaiping (24.12%), followed by G6PD Canton (17.91%), and G6PD Gaohe (11.28%). We compared the G6PD mutation spectrum among Zhuang, Han and other Southeast Asian populations, and the Zhuang population's mutation distribution was quite similar to that in the Han population. Conclusion: This study provided a detailed G6PD mutation spectrum in Baise of southwestern China and will be valuable for the diagnosis and research of G6PD deficiency in this area. Furthermore, the SNPscan assay could be used to quickly diagnose these G6PD mutations accurately.

Molecular genotyping of G6PD mutations for neonates in Ningbo area

The aim of this study is to determine the cut-off value of glucose-6-phosphate dehydrogenase (G6PD) activity and the mutation spectrum of G6PD gene in neonates with G6PD deficiency at Ningbo. Around 82233 neonatal blood samples were measured to determine G6PD activity. The positive samples were further detected with gene analysis. A total of 445 neonates were confirmed as G6PD deficiency, and the incidence in Ningbo was 1/185. 17 types of G6PD gene mutations were found, including 11 single-site mutations and 6 double-site mutations. Considering the significant differences in G6PD activity, the cut-off value was detected to be 2.35 and 3.65 U/gHb for males and females, respectively. Significant differences in G6PD activities were noted and found to be varied from 4.61 to 6.02 U/gHb in different seasons (p < 0.0001). G6PD deficiency screening is a significant detection test for neonatal G6PD deficiency prevention. Our study highlights that the screening should be done using different cut-off values according to the sexes in different seasons.

Molecular Characterization of Glucose-6-Phosphate Dehydrogenase Deficiency in the Shenzhen Population

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is caused by one or more mutations in the G6PD gene on chromosome X. This study aimed to characterize the G6PD gene variant distribution in Shenzhen of Guangdong province.

METHODS

A total of 33,562 individuals were selected at the hospital for retrospective analysis, of which 1,213 cases with enzymatic activity-confirmed G6PD deficiency were screened for G6PD gene variants. Amplification refractory mutation system PCR was first used to screen the 6 dominant mutants in the Chinese population (c.1376G>T, c.1388G>A, c.95A>G, c.1024C>T, c.392G>T, and c.871G>A). If the 6 hotspot variants were not found, next-generation sequencing was then performed. Finally, Sanger sequencing was used to verify all the mutations.

RESULTS

The incidence of G6PD deficiency in this study was 3.54%. A total of 26 kinds of mutants were found in the coding region, except for c.-8-624T>C, which was in the noncoding region. c.1376G>T and c.1388G>A, both located in exon 12, were the top 2 mutants, accounting for 68.43% of all individuals. The 6 hotspot mutations had a cumulative proportion of 94.02%.

CONCLUSIONS

This study provided detailed characteristics of G6PD gene variants in Shenzhen, and the results would be valuable to enrich the knowledge of G6PD deficiency.

Molecular characterization of G6PD mutations reveals the high frequency of G6PD Aures in the Lao Theung population

Background

The prevalence and genotypes of G6PD deficiency vary worldwide, with higher prevalence in malaria endemic areas. The first-time assessment of G6PD deficiency prevalence and molecular characterization of G6PD mutations in the Lao Theung population were performed in this study.

Methods

A total of 252 unrelated Lao Theung participants residing in the Lao People’s Democratic Republic (PDR) were recruited. All participant samples were tested for G6PD enzyme activity and G6PD gene mutations. The amplification refractory mutation system (ARMS)-PCR for detecting G6PD Aures was developed.

Results

The G6PD mutations were detected in 11.51% (29/252) of the participants. Eight G6PD mutations were detected. The G6PD Aures was the most common mutation identified in this cohort, which represented 58.62% (17/29) of all mutation. The mutation pattern was homogenous, predominantly involving the G6PD Aures mutation (6.75%), followed by 1.19% G6PD Union and 0.79% each G6PD Jammu, G6PD Mahidol and G6PD Kaiping. One subject (0.4%) each carried G6PD Viangchan and G6PD Canton. Interestingly, one case of coinheritance of G6PD Aures and Quing Yan was detected in this cohort. Based on levels of G6PD enzyme activity, the prevalence of G6PD deficiency in the Lao Theung population was 9.13% (23/252). The prevalence of G6PD deficient males and females (activity < 30%) in the Lao Theung population was 6.41% (5/78) and 1.72% (3/174), respectively, and the prevalence of G6PD intermediate (activity 30–70%) was 5.95% (15/252).

Conclusions

The G6PD Aures mutation is highly prevalent in the Lao Theung ethnic group. The common G6PD variants in continental Southeast Asian populations, G6PD Viangchan, Canton, Kaiping, Union and Mahidol, were not prevalent in this ethnic group. The technical simplicity of the developed ARMS-PCR will facilitate the final diagnosis of the G6PD Aures.

Epidemiology, evolutionary origin, and malaria-induced positive selection effects of G6PD-deficient alleles in Chinese populations

BACKGROUND

Although glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common inherited disorder in the Chinese population, there is scarce evidence regarding the epidemiology, evolutionary origin, and malaria-induced positive selection effects of G6PD-deficient alleles in various Chinese ethnic populations.

METHODS

We performed a large population-based screening (n = 15,690) to examine the impact of selection on human nucleotide diversity and to infer the evolutionary history of the most common deficiency alleles in Chinese populations.

RESULTS

The frequencies of G6PD deficiency ranged from 0% to 11.6% in 12 Chinese ethnic populations. A frequency map based on geographic information showed that G6PD deficiency was highly correlated with historical malaria prevalence in China and was affected by altitude and latitude. The five most frequently occurring G6PD gene variants were NM_001042351.3:c.1376G>T, NM_001042351.3:c.1388G>A, NM_001042351.3:c.95A>G, NM_001042351.3:c.1311T>C, and NM_001042351.3:c.1024C>T, which were distributed with ethnic features. A pathogenic but rarely reported variant site (NM_001042351.3:c.448G>A) was identified in this study. Bioinformatic analysis revealed a strong and recent positive selection targeting the NM_001042351.3:c.1376G>T allele that originated in the past 3125 to 3750 years and another selection targeting the NM_001042351.3:c.1388G>A allele that originated in the past 5000 to 6000 years. Additionally, both alleles originated from a single ancestor.

CONCLUSION

These results indicate that malaria has had a major impact on the Chinese genome since the introduction of rice agriculture.