Molecular epidemiological investigation of G6PD deficiency by a gene chip among Chinese Hakka of southern Jiangxi province.
ABSTRACT: In southern China, glucose-6-phosphate dehydrogenase (G6PD) deficiency is a significant health problem, and the incidence ranged from 0.5 to 4.08% in different Chinese population. The aims of this study are to investigate the molecular epidemiological characteristic of the G6PD gene among Chinese Hakka in southern Jiangxi province. 2331 unrelated subjects were screened for G6PD deficiency by a fluorescent test. DNA from deficient individuals was analyzed by a gene chip analysis for thirteen common Chinese G6PD mutations. In total, 3.60% (82/2331; 95% CI 2.77-4.27) of the sample were found to be G6PD-deficient. Eight mutations were found from 80 samples. However, mutation(s) for the two remaining samples were unknown. The most common mutations were G6PD Canton (1376 G>T) and G6PD Kaiping (1388 G>A), and the following mutations were 1311 polymorphism (1311 C>T), G6PD Gaohe (95 A>G), G6PD Chinese-5 (1024 C>T), G6PD Maewo (1360 C>T), Shunde (592 C>T), G6PD Viangchan (871 G>A) and Chinese-3 (493 A>G). This is the first report of G6PD deficiency among Chinese Hakka population in Jiangxi province.
Project description:BACKGROUND In southern China, glucose-6-phosphate dehydrogenase (G6PD) deficiency is a significant health problem. The aim of this study was to investigate the molecular epidemiological characteristic of the G6PD gene among Chinese Hakka in southern Guangdong province. MATERIAL AND METHODS We screened 611 unrelated subjects for G6PD genetic polymorphism analyzed by a gene chip analysis for common Chinese G6PD mutations. G-6-PD enzyme activity was determined by use of the G-6-PD quantitative detection kit. RESULTS Seven mutation sites were detected from subjects in our study. G6PD Canton (c.1376 G?T)(33.06%), G6PD Kaiping (c.1388 G?A)(30.67%), and polymorphism (c.1311 C?T)(25.89%) account for 89.62% of mutations, followed by G6PD Gaohe (c.95 A?G)(5.97%), G6PD Chinese-5 (c.1024 C?T)(3.58%), G6PD Maewo (c.1360 C?T)(0.39%), and G6PD Viangchan (c.871G?A)(0.39%). CONCLUSIONS We studied the genetic polymorphisms and frequencies of G6PD gene in the Hakka population of Meizhou. Our results coincide with the results among the Chinese Jiangxi Hakka population. It was consistent with previous research reports on Chinese people. There were differences in the results of reports from some other Asian populations. Our results could be useful for future prevention and control of G6PD deficiency aimed at the Chinese Hakka population.
Project description:Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy in humans, affecting ~ 500 million worldwide. A detailed study of the structural stability and catalytic activity of G6PD variants is required to understand how different mutations cause varying degrees of enzyme deficiency, reflecting the response of G6PD variants to oxidative stress. Furthermore, for G6PD double variants, investigating how two mutations jointly cause severe enzyme deficiency is important. Here, we characterized the functional and structural properties of nine G6PD variants: G6PD Gaohe, G6PD Mahidol, G6PD Shoklo, G6PD Canton, G6PD Kaiping, G6PD Gaohe + Kaiping, G6PD Mahidol + Canton, G6PD Mahidol + Kaiping and G6PD Canton + Kaiping. All variants were less catalytically active and structurally stable than the wild type enzyme, with G6PD double mutations having a greater impact than single mutations. G6PD Shoklo and G6PD Canton + Kaiping were the least catalytically active single and double variants, respectively. The combined effects of two mutations were observed, with the Canton mutation reducing structural stability and the Kaiping mutation increasing it in the double mutations. Severe enzyme deficiency in the double mutants was mainly determined by the trade-off between protein stability and catalytic activity. Additionally, it was demonstrated that AG1, a G6PD activator, only marginally increased G6PD enzymatic activity and stability.
Project description:OBJECTIVE:The aim of the study was to explore genotype distribution thalassemia and G6PD deficiency in Meizhou city, China. METHODS:A total of 16 158 individuals were involved in thalassemia genetic testing. A total of 605 subjects were screened for common Chinese G6PD mutations by gene chip analysis. Genotypes and allele frequencies were analyzed. RESULTS:A total of 5463 cases carried thalassemia mutations were identified, including 3585 cases, 1701 cases, and 177 cases with ?-, ?-, and ? + ?-thalassemia mutations, respectively. --SEA (65.12%), -?3.7 (19.05%), and -?4.2 (8.05%) deletion were the main mutations of ?-thalassemia, while IVS-II-654(C ? T) (40.39%), CD41-42(-TCTT) (32.72%), -28(A ? G) (10.11%), and CD17(A ? T) (9.32%) mutations were the principal mutations of ?-thalassemia in Meizhou. There were significant differences in allele frequencies in some counties. Genetic testing for G6PD deficiency, six mutation sites, and one polymorphism were detected in our study. A total of 198 alleles with the mutation were detected among 805 alleles (24.6%). G6PD Canton (c.1376 G ? T) (45.96%), G6PD Kaiping (c.1388 G ? A) (39.39%), and G6PD Gaohe (c.95 A ? G) (9.09%) account for 94.44% mutations, followed by G6PD Chinese-5 (c.1024 C ? T) (4.04%), G6PD Viangchan (c.871G ? A) (1.01%), and G6PD Maewo (c.1360 C ? T) (0.51%). There were some differences of the distribution of G6PD mutations among eight counties in Meizhou. CONCLUSIONS:The --SEA , -?3.7 , and -?4.2 deletion were the main mutations of ?-thalassemia, while IVS-II-654(C ? T), CD41-42(-TCTT), -28(A ? G), and CD17(A ? T) mutations were the principal mutations of ?-thalassemia in Meizhou. G6PD c.1376 G ? T, c.1388 G ? A, and c.95 A ? G were the main mutations of G6PD deficiency. There were some differences of the distribution of thalassemia and G6PD mutations among eight counties in Meizhou.
Project description:BACKGROUND: G6PD deficiency is common in malaria endemic regions and is estimated to affect more than 400 million people worldwide. Treatment of malaria patients with the anti-malarial drug primaquine or other 8-aminoquinolines may be associated with potential haemolytic anaemia. The aim of the present study was to investigate the prevalence of G6PD variants in Thai population who resided in malaria endemic areas (western, northern, north-eastern, southern, eastern and central regions) of Thailand, as well as the Burmese population who resided in areas along the Thai-Myanmar border. METHODS: The ten common G6PD variants were investigated in dried blood spot samples collected from 317 Thai (84 males, 233 females) and 183 Burmese (11 males, 172 females) populations residing in malaria endemic areas of Thailand using PCR-RFLP method. RESULTS: Four and seven G6PD variants were observed in samples collected from Burmese and Thai population, with prevalence of 6.6% (21/317) and 14.2% (26/183), respectively. Almost all (96.2%) of G6PD mutation samples collected from Burmese population carried G6PD Mahidol variant; only one sample (3.8%) carried G6PD Kaiping variant. For the Thai population, G6PD Mahidol (8/21: 38.1%) was the most common variant detected, followed by G6PD Viangchan (4/21: 19.0%), G6PD Chinese 4 (3/21: 14.3%), G6PD Canton (2/21: 9.5%), G6PD Union (2/21: 9.5%), G6PD Kaiping (1/21: 4.8%), and G6PD Gaohe (1/21: 4.8%). No G6PD Chinese 3, Chinese 5 and Coimbra variants were found. With this limited sample size, there appeared to be variation in G6PD mutation variants in samples obtained from Thai population in different regions particularly in the western region. CONCLUSIONS: Results indicate difference in the prevalence and distribution of G6PD gene variants among the Thai and Burmese populations in different malaria endemic areas. Dosage regimen of primaquine for treatment of both Plasmodium falciparum and Plasmodium vivax malaria may need to be optimized, based on endemic areas with supporting data on G6PD variants. Larger sample size from different malaria endemic is required to obtain accurate genetic mapping of G6PD variants in Burmese and Thai population residing in malaria endemic areas of Thailand.
Project description:Primaquine is an effective anti-hypnozoite drug for <i>Plasmodium vivax</i> and <i>Plasmodium ovale.</i> However, it can trigger erythrocyte hemolysis in people with glucose 6-phosphate dehydrogenase (G6PD) deficiency. In a previous report from South Central Timor (SCT), Indonesia, we described the prevalence of Vanua Lava, Chatham, and Viangchan variants; in this study, other G6PD variants (Kaiping, Coimbra, Gaohe, Canton, and Mahidol) were subsequently analyzed. For clarity, all of these results are described together. The 381 DNA samples from the previous study during 2013-2014 were analyzed for G6PD variants by using PCR-restriction fragment length polymorphism (RFLP). The prevalence of G6PD deficiency in SCT was 6.3% (24/381 cases), including 4.2% (16/381 cases), 0.5% (2/381 cases), and 1.6% (6/381 cases) for Coimbra, Kaiping, and Vanua Lava variants, respectively. No other variants were found in this population. A significant association was found between ethnicity and the distribution of G6PD Kaiping in female subjects. A positive association was shown between G6PD activity and heterozygous females carrying Coimbra genotype, hemizygous males carrying Vanua Lava, <i>Plasmodium falciparum</i> infection in female subjects, and <i>P. vivax</i> infection in male subjects. Further molecular analysis of heterozygous females, particularly in malaria-endemic areas, is needed for mapping distribution of G6PD deficiency status in Indonesia.
Project description:Human glucose-6-phosphate dehydrogenase deficiency (G6PD) is mostly caused by single nucleotide change in the G6PD gene which leads to single amino acid substitution. Previous trials suggested a few samples had decreased ratio of G6PD/6PGD(<1.00) but no mutation detected by multiple methods. In 138 cases of Chinese children with G6PD deficiency, RT-PCR combined with DNA Sequencing was performed to screen the mutations in the coding region and promoter region of G6PD gene. The mutation detection frequency by this method was 100 %, including a novel missense mutation (1088 A>T) and 13 mutations reported before. The novel mutation predicted an Asn-to-Ile substitution at codon 363, which was identified in a male infant patient. The variant caused by this mutation had reduced enzymatic activity, belonging to WHO Class I. Synonymous or missense mutation was not found in the proximal promoter region of the G6PD gene, which was consistent with earlier findings that G6PD deficiency was not associated with promoter mutations in the G6PD gene. RT-PCR combined with DNA Sequencing could be another alternative for clinically molecular diagnosis of G6PD deficiency.
Project description:BACKGROUND:Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzymopathy. The human G6PD gene is highly polymorphic, and over 200 mutations have been identified, many of which are associated with hemolytic anemia. Here, we analyzed the clinical genetics data of a Chinese girl with favism who developed acute hemolytic anemia after fava bean ingestion. METHODS:The clinical genetics data of the proband who developed acute hemolytic anemia were collected and analyzed, and G6PD gene exons were sequenced in the proband and her family. RESULTS:We reported for the first time a novel G6PD gene variant in a Chinese girl, which we named "G6PD Wuhan." This variant is localized exon 3 of the G6PD gene at genomic position 141G > C, that is a change from p.Lys47 to Asn. The bioinformatics analysis and protein modeling study indicated this variant may have negative effects on the enzyme activity of G6PD. CONCLUSIONS:Our results indicated that favism in the proband was caused by this novel heterozygous variant (c.141G > C) in G6PD. The variant in G6PD has implications for genetic counseling and could provide insights into the functional roles of G6PD mutations.
Project description:Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the most common red cell disorders in the world. The aim of this study was to investigate whether the G6PD Mahidol variant and haplotype 1311?T/93C, which are prevalent in the Kachin ethnic population along the China-Myanmar border area, offer protection against Plasmodium vivax infection. Malaria was monitored in nine villages near the Laiza township, Kachin State, Myanmar, where 258 cases of uncomplicated P. vivax were identified in 2013-2017. From the same villages, 250 unrelated, malaria-free participants were recruited to serve as the control cohort. Quantitative enzyme activity analysis in 100 healthy individuals identified that both male hemizygotes and female heterozygotes of the G6PD Mahidol variant had on average ~40% lower enzyme activity relative to the wild-type individuals. Compared with the overall prevalence of 25.2% in the control cohort, the G6PD Mahidol variant had a significantly lower prevalence (7.0%) among the 258 vivax patients (P?< ?.0001, ?2 test). Logistic regression analysis of G6PD genotypes stratified by sex showed that the individuals with the Mahidol 487A allele had dramatically reduced odds of having acute vivax malaria (adjusted odds ratio?=?0.213 for male 487A hemizygotes, P?<?.0001, and 0.248 for female 487GA heterozygotes, P?<?.001). Furthermore, both 487A hemizygous male and 487GA heterozygous female patients had significantly lower asexual parasitemias than the wild-type patients, suggesting a potential effect on alleviating disease severity. In contrast, the silent mutation haplotype 1311?T/93C was highly prevalent (49.6%) in the study population, but it was not associated with altered G6PD enzymatic activities nor did it seem to provide protection against vivax infection or disease severity. Taken together, this study provided evidence that the Mahidol G?>?A mutation offers protection against P. vivax infection and potentially reduces disease severity in a Kachin population.
Project description:Deficiency of glucose-6-phosphate dehydrogenase (G6PD) is the single most common enzymopathy, present in approximately 400 million humans (approximately 5%). Its prevalence is hypothesized to be due to conferring resistance to malaria. However, G6PD deficiency also results in hemolytic sequelae from oxidant stress. Moreover, G6PD deficiency is associated with kidney disease, diabetes, pulmonary hypertension, immunological defects, and neurodegenerative diseases. To date, the only available mouse models have decreased levels of WT stable G6PD caused by promoter mutations. However, human G6PD mutations are missense mutations that result in decreased enzymatic stability. As such, this results in very low activity in red blood cells (RBCs) that cannot synthesize new protein. To generate a more accurate model, the human sequence for a severe form of G6PD deficiency, Med(-), was knocked into the murine G6PD locus. As predicted, G6PD levels were extremely low in RBCs, and deficient mice had increased hemolytic sequelae to oxidant stress. Nonerythroid organs had metabolic changes consistent with mild G6PD deficiency, consistent with what has been observed in humans. Juxtaposition of G6PD-deficient and WT mice revealed altered lipid metabolism in multiple organ systems. Together, these findings both establish a mouse model of G6PD deficiency that more accurately reflects human G6PD deficiency and advance our basic understanding of altered metabolism in this setting.
Project description:BACKGROUND:Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most prevalent inborn disorder. This X-chromosome-linked recessive disease affects more than 400 million people globally, and is associated with haemolytic anaemia after medication with the anti-latent malaria drug, primaquine. To prevent malaria, the Republic of Korea (ROK) Army administers malaria chemoprophylaxis. Due to the previously low G6PD deficiency prevalence in the ROK, prior to primaquine administration, testing for G6PD deficiency was not mandatory. In this study, to evaluate the risk from malaria chemoprophylaxis in the ROK, G6PD deficiency prevalence was investigated. METHODS:Blood specimens from 1632 soldiers entering training camp for the 3rd Infantry of the ROK Army were collected. CareStart™ Biosensor for G6PD and haemoglobin (Hb) was used to detect G6PD levels. G6PD variants using the DiaPlexC G6PD Genotyping kit (Asian type) and full-length sequencing were examined. RESULTS:Of 1632 blood specimens tested, none was observed to be G6PD deficient. The median value of all tested samples was 7.582 U/g Hb. An investigation of 170 G6PD DNA variants was analysed and categorized as partially low normal [n?=?131, 30-80% (2.27-6.05 U/g Hb) of the median value], high [n?=?3, >?150% (>?11.373 U/g Hb) of the median value], or normal [n?=?36, 80-150% (6.05-11.373 U/g Hb) of the median value], and none was amplified by the DiaPlexC kit. Five silent mutations (C?T) in 131 partially low normal specimens were found at the 1311th nucleotide position by sequence analysis. Another 8 silent mutations (T93C) were also detected in 131 partially low normal specimens. Thus, it is inferred that these silent mutations could be related to G6PD activity. CONCLUSIONS:This G6PD deficiency prevalence study, conducted among participants from the 3rd Infantry of the ROK Army, provided crucial evidence for the safety of malaria chemoprophylaxis. This study showed that the prevalence of G6PD deficiency among 1632 young soldiers was wholly absent. Although G6PD phenotypic mutations were not detected, many silent mutations (C1311T and T93C) were observed. Thus, it is inferred that malaria chemoprophylaxis is relatively safe against G6PD deficiency-mediated haemolytic anaemia. However, given the number of individuals whose G6PD were at the partially low normal range and the frequent detection of G6PD deficiency-related mutations, consistent monitoring of G6PD deficiency is needed.