Glucose‐6‐phosphate dehydrogenase (G6PD) mutations in Thailand: G6PD Viangchan (871G>A) is the most common deficiency variant in the Thai population

Glucose‐6‐phosphate dehydrogenase (G6PD) deficiency is the most common hereditary disorder in humans. Through a population study for G6PD deficiency using a cord blood quantitative G6PD assay in Bangkok, Thailand, we found that the prevalence of G6PD deficiency is 11.1% in Thai male (N=350) and 5.8% in female (N=172) cord blood samples. Among the neonates with hyperbilirubinemia, the prevalence of G6PD deficiency is 22.1% in males (N=140) and 10.1% in females (N=89). We developed a PCR‐restriction enzyme‐based method to identify G6PD Viangchan (871G>A), and searched for this and 9 other mutations in DNA from G6PD deficient blood samples. G6PD Viangchan (871G>A) was the most common mutation identified (54%), followed by G6PD Canton (1376G>T; 10%), G6PD Mahidol (487G>A; 8%), G6PD Kaiping (1388G>A; 5%), G6PD Union (1360C>T; 2.6%) and “Chinese‐5” (1024C>T; 2.6%). Among 20 neonates with hyperbilirubinemia, G6PD Viangchan was also most frequently identified (60%), followed by G6PD Canton (10%), G6PD Mahidol, G6PD Union, and G6PD Kaiping (5% each). G6PD Viangchan appears from this study to be the most common G6PD mutation in the Thai population, bringing into question previous reports that G6PD Mahidol is most prevalent. G6PD Viangchan, together with G6PD Mahidol and G6PD Canton, are responsible for over 70% of G6PD deficiency in this study of Thais. With the data from other Southeast Asian ethnic groups such as Laotians, G6PD Viangchan (871G>A) is probably the most common variant in non‐Chinese Southeast Asian population.© 2002 Wiley‐Liss, Inc.     

Complete molecular characterisation of glucose-6-phosphate dehydrogenase (G6PD) deficiency in a group of Malaysian Chinese neonates

We performed DNA analysis on cord blood samples of 128 Chinese male neonates diagnosed as G6PD deficiency in Hospital Universiti Kebangsaan Malaysia by a combination PCR-restriction enzyme digest technique, Single Stranded Conformation Polymorphism analysis and DNA sequencing. We found 10 different G6PD-deficient mutations exist. The two commonest alleles were G6PD Canton 1376 G>T (42.3%) and Kaiping 1388 G>A (39.4%) followed by G6PD Gaohe 592 G>A (7.0%), Chinese-5 1024 C>T, Nankang 517 T>C (1.5%), Mahidol 487 G>A (1.6%), Chatham 1003 G>T (0.8%), Union 1360 C>T (0.8%), Viangchan 871 G>A (0.8%) and Quing Yang 392 G>T (0.8%). Sixty eight percent (88/125) neonates in this study had neonatal jaundice and 29.7% developed hyperbilirubinemia >250 micromol/l. The incidence of hyperbilirubinemia >250 micromol/l was higher in G6PD Kaiping (43.8%) than G6PD Canton (22%) (p< 0.05). There was no significant difference in the incidence of neonatal jaundice, mean serum bilirubin, mean age for peak serum bilirubin, percentage of babies requiring phototherapy and mean duration of phototherapy between the two major variants. None of the 88 neonates required exchange transfusion. In conclusion we have completely characterized the molecular defects of a group of Chinese G6PD deficiency in Malaysia. The mutation distribution reflects the original genetic pool and limited ethnic admixture with indigenous Malays.     

Glucose-6-phosphate dehydrogenase deficiency in Chinese

In a Chinese population 1,000 full-term male neonates and a further 117 jaundiced neonates of both sexes were studied in an investigation of the frequency of deficiency of erythrocyte glucose-6-phosphate dehydrogenase (G6PD). This enzyme was found to be deficient in 3.6% of male neonates. Correlation of the results with the birthplace of the 602 mothers who were known to come from Kwangtung province showed no significant differences in the frequency of the deficiency between certain parts of the province.The deficiency of G6PD in hemizygous males is profound but it is not associated with erythrocyte acid monophosphoesterase deficiency in Chinese in Hong Kong. The G6PD deficiency accounts for 15.4% of all the 117 cases of neonatal jaundice. The relative importance of G6PD deficiency as a cause of neonatal jaundice does not differ materially in male and female mutants. Neonatal jaundice can occur in all genotypes of G6PD mutation in Chinese.     

湖南地区小儿葡萄糖-6-磷酸脱氢酶三种基因型突变及其临床表现

目的探讨湖南地区小儿葡萄糖-6-磷酸脱氢酶(G6PD)的3种常见基因突变类型与临床表现的关系.方法使用突变特异性扩增系统(ARMS)法,对168例经G6PD/6PGD比值法证实为G6PD缺乏症患儿的静脉血进行3种点突变检测,并对其进行临床分析.结果168例中检出G1388A 37例发生率22%,G1376T74例发生率44%,A95G 45例发生率26.8%,未定型12例发生率7.2%.3种常见基因突变型均能导致严重的酶活性缺陷和急性溶血性贫血、不同程度黄疸等症状.结论G1376T、G1388A、A95G突变型是湖南人最常见G6PD基因突变类型,3种突变型患者具有相似的临床表现.     

Glucose-6-phosphate dehydrogenase (G6PD) variants in Malaysian Malays

We performed DNA analysis using cord blood samples on 86 male Malay neonates diagnosed as G6PD deficiency in the National University of Malaysia Hospital by a combination of rapid PCR-based techniques, single-stranded conformation polymorphism analysis (SSCP) and DNA sequencing. We found 37.2% were 871G>A (G6PD Viangchan), 26.7% were nt 563 C>T (G6PD Mediterranean) and 15.1% were 487G>A (G6PD Mahidol) followed by 4.7% 1376G>T (G6PD Canton), 3.5% 383T>C (G6PD Vanua Lava), 3.5% 592C>T (G6PD Coimbra), 2.3% 1388G>A (G6PD Kaiping), 2.3% 1360C>T (G6PD Union), 2.3% 1003G>A (G6PD Chatham), 1.2% 131C>G (G6PD Orissa) and 1.2% 1361G>A (G6PD Andalus). Seventy-one (82.6%) of the 86 G6PD-deficient neonates had neonatal jaundice. Fifty seven (80%) of the 71 neonates with jaundice required phototherapy with only one neonate progressing to severe hyperbilirubinemia (serum bilirubin >340 micromol/l) requiring exchange transfusion. There was no significant difference in the incidence of neonatal jaundice, mean serum bilirubin level, mean age for peak serum bilirubin, percentage of babies requiring phototherapy and mean number of days of phototherapy between the three common variants. In conclusion, the molecular defects of Malay G6PD deficiency is heterogeneous and G6PD Viangchan, Mahidol and Mediterranean account for at least 80% of the cases. Our findings support the observation that G6PD Viangchan and Mahidol are common Southeast Asian variants. Their presence in the Malays suggests a common ancestral origin with the Cambodians, Laotians and Thais. Our findings together with other preliminary data on the presence of the Mediterranean variant in this region provide evidence of strong Arab influence in the Malay Archipelago.     

Molecular epidemiological investigation of G6PD deficiency by a gene chip among Chinese Hakka of southern Jiangxi province

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.     

Chinese newborn screening for the incidence of G6PD deficiency and variant of G6PD gene from 2013 to 2017

Glucose‐6‐phosphate dehydrogenase (G6PD) deficiency is one of the most common X‐linked enzymopathies caused by G6PD gene variant. We aimed to provide the characteristics of G6PD deficiency and G6PD gene variant distribution in a large Chinese newborn screening population. We investigated the prevalence of G6PD in China from 2013 to 2017. Then, we examined G6PD activity and G6PD gene in representative Chinese birth cohort to explore the distribution of G6PD gene variant in 2016. We then performed multicolor melting curve analysis to classify G6PD gene variants in 10,357 neonates with activity‐confirmed G6PD deficiency, and DNA Sanger sequencing for G6PD coding exons if hot site variants were not found. The screened population, organizations, and provinces of G6PD deficiency were increased from 2013 to 2017 in China. The top five frequency of G6PD gene variants were c.1376G>T, c.1388G>A, c.95A>G, c.1024C>T, and c.871G>A and varied in different provinces, with regional and ethnic features, and four pathogenic variant sites (c.152C>T, c.290A>T, c.697G>C, and c.1285A>G) were first reported. G6PD deficiency mainly occurs in South China, and the frequency of G6PD gene variant varies in different regions and ethnicities.     

Further investigations of glucose-6-phosphate dehydrogenase variants in Flores Island, eastern Indonesia

We conducted field surveys for malaria and glucose-6-phosphate dehydrogenase (G6PD) deficiency in the eastern part of Flores Island, East Nusa Tenggara Province, Indonesia. A total of 1,108 volunteers (642 males and 466 females) belonging to three ethnic groups (Sikka, Ende and Bajo) were examined, and 55 G6PD-deficient individuals (38 males and 17 females) were detected. Among them, 50 samples were analyzed molecularly, in addition to three deficient cases in a Bajo family. In the Sikka population, G6PD Kaiping (1388G>A), one of the two common variants in the Chinese population, was unexpectedly found as the most dominant variant (11/22, 50.0%), followed by G6PD Chatham (1003G>A, 36.4%), G6PD Coimbra (592C>T, 9.1%) and G6PD Vanua Lava (383T>C, 4.5%). Frequency of G6PD Kaiping in the Sikka might be the highest among non-Chinese populations reported so far. In the Ende population, G6PD Vanua Lava (9/14, 64.3%) was the highest, followed by G6PD Kaiping (14.3%), G6PD Chinese-5 (1024C>T, 14.3%) and G6PD Chatham (7.1%). In the Bajo population, a total of 18 deficient cases were analyzed, and a novel mutation (844G>T) in exon 8 with a predicted amino acid change of 282 Asp>Tyr was found in a 7-year-old boy at a Bajo village near Maumere. This new Class II (mild type) variant was also confirmed in his mother and sister, and designated as G6PD Bajo Maumere. The missense mutation at the same nucleotide 844 has been known as G6PD Seattle/Lodi/Modena/Ferrara II, but this mutation is caused by a G>C substitution (282 Asp>His). In the Bajo population, G6PD Viangchan (871G>A, IVS 11 nt93 T>C, 1311C>T), the most common variant in continental Southeast Asian populations, was found to be the dominant (11/18, 61.1%), followed by G6PD Vanua Lava and the new variant (each 16.7%), and G6PD Coimbra (5.6%). These results strongly suggest that the Bajo peoples may have different ancestors from those for Sikka and Ende, and may be much closer to continental Southeast Asian populations. It is interesting that G6PD Canton (1376G>T), another common variant in Chinese, was not seen in the Flores population.     

Prevalence of uridine glucuronosyl transferase 1A1 (UGT1A1) mutations in Malay neonates with severe jaundice

A number of genetic risk factors have been implicated in the development of neonatal severe hyperbilirubinaemia. This includes mutations in the uridine glucoronosyl transferase 1A1 (UGT1A1) gene which is responsible for unconjugated hyperbilirubinemia in Gilbert's Syndrome. We studied the prevalence of UGT1A1 gene mutations in a group of Malay neonates to determine whether they are risk factors to severe neonatal jaundice. One hundred and twenty-five Malay neonates with severe hyperbilirubinemia were studied. Ninety-eight infants without severe hyperbilirubinaemia were randomly selected from healthy Malay term infants (controls). DNA from EDTA cord blood samples were examined for UGT1A1 mutations nt211G > A and nt247T > C using established Taqman SNP genotyping assays and the UGT1A1*28 variant was detected by the Agilent 2100 bioanalyzer. All samples were also screened for common Malay G6PD variants using established techniques. The frequency of UGT1A1 211G > A mutation is significantly higher in the severely hyperbilirubinemic group (13%) than the control group (4%; p = 0.015) and all the positive cases were heterozygous for the mutation. There was no significant difference in the frequency of UGT1A1*28 mutation between the severely hyperbilirubinemic (3.5%) and the control group (0.01%; p = 0.09). None of the neonates in both groups carried the nt247 T > C mutation. The prevalence of G6PD mutation was significantly higher in the severely jaundiced group than control (9% vs 4%; p = 0.04). In conclusion, nt 211 G > A alleles constitute at least 12% of UGT1A1 mutations underlying unconjugated hyperbilirubinemia and appears to be a significant independent risk factor associated with severe neonatal hyperbilirubinemia in the Malay newborns.     

G6PD Viangchan (871G>A) is the most common G6PD-deficient variant in the Cambodian population

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common hereditary enzymopathy among Southeast Asians. We studied G6PD mutations in 108 migrant Cambodian laborers in Chanthaburi province and cord blood samples from 107 Cambodian newborns at Buriram Hospital. Thirty-one (26.1%) of 119 Cambodian males and three of 96 (3.1%) females were G6PD deficient and were assayed for G6PD mutations. G6PD Viangchan (871G>A) was identified in most G6PD-deficient Cambodians (28 of 34; 82.4%); G6PD Union (1360C>T) and G6PD Coimbra (592C>T) was found in one case each. We concluded that G6PD Viangchan (871G>A) was the most common mutation among Cambodians. This finding is similar to G6PD-deficient Thais and Laotians, suggesting a common ancestry of people from these three countries.     

Coexistence of five G6PD variants indicates ethnic complexity of Phuket islanders, Southern Thailand

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy in humans. The prevalence of G6PD deficiency and its molecular basis were studied in Phuket islanders, Southern Thailand. A total of 345 volunteers (123 males and 222 females) were recruited in this study. Infection with Plasmodium falciparum or Plasmodium vivax was not detected in any of these subjects by polymerase chain reaction (PCR)-based diagnosis. G6PD-deficient individuals were identified with the WST-8/1-methoxy PMS method. The molecular basis of G6PD deficiency was investigated by PCR-direct sequencing procedures or PCR-restriction enzyme fragment length polymorphism assays. The numbers of individuals showing severe and mild G6PD deficiency were 14 and 21, respectively. A high prevalence of G6PD deficiency was observed in subjects with Moken (15.4%) or Thai (15.5%) ethnic background. G6PD Mahidol (487G>A) (n=14), G6PD Viangchan (871G>A) (n=11), G6PD Gaohe (95A>G) (n=2), G6PD Kaiping (1388G>A) (n=1), and G6PD Kerala-Kalyan (949G>A) (n=1) were identified. The results suggest that several groups of people of the Asian Continent, such as Burmese, Laotian or Cambodian, Thai and Chinese, participated in the establishment of the ethnic identity of the current ethnic groups of Phuket Island.     

Glucose-6-phosphate dehydrogenase mutations in Mon and Burmese of southern Myanmar

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is highly prevalent in Southeast Asians. G6PD mutations are associated with specific ethnic groups in Southeast Asia. Mon is a minority ethnic group in Myanmar, which speaks Monic, a distinct language of Mon-Khmer classification. We studied G6PD mutations in Mon and Burmese males of southern Myanmar who migrated to Thailand in Samutsakhon province. G6PD deficiency was identified in 19 (12%) of 162 Mon males and 17 (10%) of 178 Burmese males, and then assayed for G6PD mutations. Among 19 G6PD-deficient Mons, 12 were G6PD Mahidol; one case each was G6PD Jammu (871G > A; nt 1311C), G6PD Kaiping (1388G > A), G6PD Mediterranean (563C > T), a novel mutation 94(C > G); and three remain unidentified. Among 17 G6PD-deficient Burmese, 12 were G6PD Mahidol; one each was G6PD Coimbra (592C > T), G6PD Kerala-Kalyan (949G > A), and G6PD Valladolid (406C > T); and two remain unidentified. G6PD Mahidol (487G > A) is the most common mutation among Mons and Burmese. All G6PD deficient Mon and Burmese, except for a person with G6PD Valladolid, shared the same haplotype nt93T, nt1311C. Despite a similar language root with Cambodian’s Khmer language, our study suggests that Mon people share a common ancestry with Burmese rather than Cambodians.     

1281例G-6-PD缺乏新生儿高胆红素血症的调查分析

目的 了解G-6-PD缺乏的新生儿高胆红素血症的发病情况，为临床防治新生儿高胆红素血症提供科学依据。方法 使用高铁血红蛋白还原试验做G-6-PD筛查，阳性者用G6PD／6PGD比值定量法进行确诊。使用重氮法测定总胆红素和直接胆红素。结果 1281例G-6-PD缺乏的新生儿高胆红素患者172例，发病率为13．4％，显著高于对照组（X^2=98，P〈0．005）；其中显著缺乏组发病率为21．2％，显著高于中间缺乏组（X^2=61．6，P〈0．005）；男性发病率为18．8％，显著高于女性（X^2=35，P〈O．005）。结论 G-6-PD缺乏是新生儿高胆红素血症的重要原因。     

Five different glucose-6-phophate dehydrogenase (G6PD) variants found among 11 G6PD-deficient persons in Flores Island, Indonesia

We conducted a survey for malaria diagnosis and treatment in four primary schools in Flores Island, one of the Indonesian Islands with an area of 17,000 km² and a population of 1.8 million. Of those examined, 24.4% were diagnosed as having malaria (90/363) and administered medicine immediately. A glucose-6-phophate dehydrogenase (G6PD) test was performed at the same time, and 16 persons (4.4%) were diagnosed as G6PD deficient. Eleven persons consented to analysis of the G6PD genome. We analyzed these subjects and found one case of G6PD Vanua Lava (383T>C), five cases of G6PD Coimbra (592C>T), one case of G6PD Viangchan (871G>A), one case of G6PD Chatham (1003G>A), and three cases of G6PD Kaiping (1388G>A). These were unexpected findings because five different G6PD variants were found in such a small population. This suggests that people of Flores Island are derived from various ancestries.     

Mutation analysis of the 6-pyruvoyl-tetrahydropterin synthase gene in Chinese hyperphenylalaninemia caused by tetrahydrobiopterin synthesis deficiency

Hyperphenylalaninemia (HPA) may be caused by deficiency of phenylalanine hydroxylase or tetrahydrobiopterin (BH₄), the essential cofactor for the aromatic amino acid hydroxylases. 6-Pyruvoyl-tetrahydropterin synthase (PTPS) deficiency is a major cause of BH₄ deficient HPA. In this study, seven single base mutations at nucleotides 73 (C>G), 155 (A>G), 166 (G>A), 209 (T>A), 259 (C>T), 286 (G>A), and 317 (C>T) on PTPS cDNA were detected in Chinese PTPS-deficient HPA by polymerase chain reaction and solid phase DNA sequencing. These nucleotide alterations result in R25G, N52S, V56M, V70D, P87S, D96N, and T106M amino acid substitutions, respectively. The R25G, V56M, V70D, and T106M were novel mutations found in PTPS gene. By analysis of 38 PTPS mutant alleles from 19 unrelated Chinese PTPS-deficient HPA families, the allele frequency of these mutations in Chinese PTPS-deficient HPA were determined to be ˜5.3% (R25G), 34.2% (N52S), 7.9% (V56M), 2.6% (V70D), 36.8% (P87S), 7.9% (D96N), and 2.6% (T106M), respectively. Two common mutations, N52S and P87S, were found to account for 71% of the Chinese PTPS mutant alleles. The N52S mutation accounts for 48% of the southern Chinese PTPS mutation, but only one (9%) of the northern Chinese PTPS mutant allele was found to be N52S, which suggested that the N52S mutation might be southern Chinese. Clinically, the V56M mutation was found to associate with the mild form of PTPS deficiency. However, the R25G, N52S, P87S, and D96N were found mainly in the patients with severe clinical symptom. Using polymerase chain reaction-based mutation analysis, a fetus at risk of PTPS deficiency was diagnosed prenatally to be a carrier of N52S mutation. Hum Mutat 11:76–83, 1998. © 1998 Wiley-Liss, Inc.     

佛山地区小儿G6PD常见基因突变型的临床研究

目的　探讨佛山地区小儿G6PD缺乏症患儿基因突变类型。方法　使用突变特异性扩增系统 (ampliticationre fractorymutationsystem ,ARMS)方法测定经G6PD/ 6磷酸葡萄糖酸脱氢酶 (6PGD)比值法二次验证的患儿 4 0例静脉血。结果　4 0例G6PD缺乏症标本男 39例 ,女 1例。经ARMS方法分析 3种已知突变。其中G1388A突变 17例 ,占 4 5 % ;G1376T突变 10例 ,占 2 5 % ;A95G突变 3例 ,占 7.5 % ,未定型 10例 ,3种常见突变共计 30例 ,占 75 %。结论　G6PD基因突变型G1388A、G1376T及A95G也是佛山地区G6PD缺乏症的常见基因突变型 ,以G1388A最多见。     

Glucose-6-phosphate dehydrogenase (G6PD) mutations in Cambodia: G6PD Viangchan (871G>A) is the most common variant in the Cambodian population

We conducted a survey of malaria diagnoses and glucose-6-phosphate dehydrogenase (G6PD) testing in remote areas of Cambodia. Blood specimens from 670 people were collected by the finger-prick method. Of these people, 24.9% were found to have malaria, and 7.0% of people were G6PD deficient. In the Khmer, the largest ethnical population in Cambodia, the G6PD deficiency rate of males was 12.6% (25/199) whereas the rates in the minorities of the Tum Pun and the Cha Ray were 1.1% (1/93) and 3.2% (2/63), respectively. Of the G6PD-deficient subjects, 97.9% (46/47) were G6PD Viangchan (871G>A), and only one case (2.1%) was G6PD Union (1360C>T). Since G6PD Mahidol (487G>A) is common in Myanmar according to our previous study, the current finding suggests that the Cambodian population is derived from homogeneous ancestries and is different from the Myanmar population. All G6PD Viangchan cases were linked to two other mutations of 1311C>T and IVS-11 nt93T>C in the G6PD gene.     

海南汉族、黎族人葡萄糖-6-磷酸脱氢酶缺乏症的基因突变型分析及一种新的G6PD基因突变型的鉴定

目的 阐明海南汉族、黎族人群中葡萄糖－6－磷酸脱氢酶缺乏症的分子基础。方法 用聚合酶链反应、限制性内切酶消化筛查了1388G→A、1360C→T、1024C→T、517T→C、493A→G、487G→A、392G→T和95A→G突变。用单链构象多态性分析筛查其它突变;用核苷酸顺序分析鉴定具有SSCP异常区带样品的突变;。结果 在59例汉族G6PD缺乏症患者中,发现1388G→A14例（23．7％）、871G→A3例（5．1％）、835A→T1例（1．7％）517T→C1例（1．7％）、392G→T3例（5．1％）95A→G4例（6．8％）;在32例黎族G6PD缺乏症患者中,发现1388G→A6例（18．8％）、871G→A3例（9．4％）和95A→G2例（6．3％）;在1例汉族患者中发现了一种新的G6PD基因突变－835A→G突变,此突变导致第279位的苏氨酸被丙氨酸取代,将此突变型命名为G6PD－海口,其酶活性约是正常的10％,此835A→T突变的活性低,后者的酶活性约是正常的40％。分析人G6PD的三维结构模型表明,第279位苏氨酸残基的羟基是维持G6PD亚基相互作用的基团。结论 海南汉族、黎族人群中具有共同的常见G6PD基因突变型;与中国其它地区人群的G6PD基因突变谱比较,结果表明某些G6PD基因突变广泛分布于中国南方不同地区人群中;G6PD第279位苏氨酸残基的可能是维持G6PD亚基相互作用及酶活性的必需基团。     

Alternative DNA-based newborn screening for glucose-6-phosphate dehydrogenase deficiency

Newborn screening for G6PD deficiency has been carried out in several countries for more than 25 years. A semi-quantitative enzymatic assay has been used in most laboratories, however, heat inactivation during the summer can cause a significant increase in the false positive rate for this assay. We have developed an alternative DNA-based newborn screening assay for the detection of common mutations within the G6PD gene. The panel of mutations includes the common African A- mutation (G202A;A376G), the common Mediterranean mutation (C563T), and two common Chinese mutations (G1376T and G1388A). A parallel study was performed through screening a total of 4245 neonatal specimens using both the enzymatic and the DNA-based assays. In this population, 49 newborns were identified as hemizygous or homozygous for the A- mutation with an average enzyme activity of 59 microM, 323 were identified as a carrier or unaffected with an average enzyme activity of 208 microM, and no mutation was detected for the remaining 3873 specimens with an average enzyme activity of 234 microM. With this panel of mutations, more than 90% of all affected infants can be identified in our population.