Genetic Analysis of Two Novel GPI Variants Disrupting H Bonds and Localization Characteristics of 55 Gene Variants Associated with Glucose-6-phosphate Isomerase Deficiency

Objective:Glucose-6-phosphate isomerase(GPI)deficiency is a rare hereditary nonspherocytic hemolytic anemia caused by GPI gene variants.This disorder exhibits wide heterogeneity in its clinical manifestations and molecular characteristics,often posing challenges for precise diagnoses using conventional methods.To this end,this study aimed to identify the novel variants responsible for GPI deficiency in a Chinese family.Methods:The clinical manifestations of the patient were summarized and analyzed for GPI deficiency phenotype diagnosis.Novel compound heterozygous variants of the GPI gene,c.174C>A(p.Asn58Lys)and c.1538G>T(p.Trp513Leu),were identified using whole-exome and Sanger sequencing.The AlphaFold program and Chimera software were used to analyze the effects of compound heterozygous variants on GPI structure.Results:By characterizing 53 GPI missense/nonsense variants from previous literature and two novel missense variants identified in this study,we found that most variants were located in exons 3,4,12,and 18,with a few localized in exons 8,9,and 14.This study identified novel compound heterozygous variants associated with GPI deficiency.These pathogenic variants disrupt hydrogen bonds formed by highly conserved GPI amino acids.Conclusion:Early family-based sequencing analyses,especially for patients with congenital anemia,can help increase diagnostic accuracy for GPI deficiency,improve child healthcare,and enable genetic counseling.

Prevalence of Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency in India: A Systematic Review

Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency is the most common enzyme deficiency of human erythrocyte affecting more than 400 million people worldwide. In India, G6PD deficiency was first reported in 1963 and since then various investigations have been conducted across country. The objective of this work was to study the prevalence of G6PD deficiency in different ethnic, caste and linguistic groups of Indian population. A systematic search of published literature was undertaken and the wide variability of G6PD deficiency has been observed ranging from 0% - 30.7% among the different caste, ethnic, and linguistic groups of India. It was observed that the incidence of G6PD deficiency was found to be considerably higher among the tribes (9.86%) as compared to other ethnic groups (7.34%) and significantly higher in males as compared to females.

Glucose-6-phosphate dehydrogenase(G6PD) deficiency is associated with asymptomatic malaria in a rural community in Burkina Faso

Objective:To investigate 4 combinations of mutations responsible for glucose-6—phosphate dehydrogenase(G6PD) deficiency in a rural community of Burkina Faso,a malaria endemic country.Methods:Two hundred individuals in a rural community were genotyped for the mutations A376 G.G202A,A542 T,G680T and T968 C using TaqMan single nucleotide polymorphism assays and polymerase chain reaction followed by restriction fragment length polymorphism.Results:The prevalence of the G6 PD deficiency was 9.5%,in the study population.It was significantly higher in men compared to women(14.23%vs 6.0%,P=0.049).The 202A/376 G G6PD Awas the only deficient variant detected.Plasmodium falciparum asymptomatic parasitemia was significantly higher among the C6PD-non—deficient persons compared to the G6PD-deficient(P<0.001).The asymptomatic parasitemia was also significantly higher among G(SPI) nondeficient compared to C6PD—heterozygous females(P<0.001).Conclusions:This study showed that the G6 PD A- variant associated with protection against asymptomatic malaria in Burkina Faso is probably the most common deficient variant.

Characterization of glucose-6-phosphate dehydrogenase deficiency and identification of a novel haplotype 487G>A/IVS5-612(G>C) in the Achang population of southwestern China

The prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency and its gene mutations were studied in the Achang population from Lianghe County in Southwestern China. We found that 7.31% (19 of 260) males and 4.35% (10 of 230) females had G6PD deficiency. The molecular analysis of G6PD gene exons 2―13 was performed by a PCR-DHPLC-Sequencing or PCR-Sequencing. Sixteen inde-pendent subjects with G6PD Mahidol (487G>A) and the new polymorphism IVS5-612 (G>C), which combined into a novel haplotype, were identified accounting for 84.2% (16/19). And 100% Achang G6PD Mahidol were linked to the IVS5-612 C. The percentage of G6PD Mahidol in the Achang group is close to that in the Myanmar population (91.3% 73/80), which implies that there are some gene flows between Achang and Myanmar populations. Interestingly, G6PD Canton (1376G>T) and G6PD Kaiping (1388G>A), which were the most common G6PD variants from other ethnic groups in China, were not found in this Achang group, suggesting that there are different G6PD mutation profiles in the Achang group and other ethnic groups in China. Our findings appear to be the first documented report on the G6PD genetics of the AChang people, which will provide important clues to the Achang ethnic group origin and will help prevention and treatment of malaria in this area.

Etiology analysis for term newborns with severe hyperbilirubinemia in eastern Guangdong of China

BACKGROUND Neonatal hyperbilirubinemia is one of the common diseases of newborns that typically presents with yellow staining of skin,resulting in sequelaes such as hearing loss,motor and intellectual development disorders,and even death.The pathogenic factors of neonatal hyperbilirubinemia are complex.Different cases of hyperbilirubinemia may have a single or mixed etiology.AIM To explore the etiological characteristics of severe hyperbilirubinemia in term newborns of eastern Guangdong of China.METHODS Term newborns with severe hyperbilirubinemia in one hospital from January 2012 to December 2021 were retrospectively analyzed.The etiology was determined according to the laboratory results and clinical manifestations.RESULTS Among 1602 term newborns with hyperbilirubinemia in eastern Guangdong of China,32.20%(580/1602)was severe hyperbilirubinemia.Among the causes of severe hyperbilirubinemia,neonatal hemolysis accounted for 15.17%,breast milk jaundice accounted for 12.09%,infection accounted for 10.17%,glucose-6-phosphate dehydrogenase(G6PD)deficiency accounted for 9.14%,and the coexistence of multiple etiologies accounted for 6.55%,unknown etiology accounted for 41.72%.ABO hemolysis and G6PD deficiency were the most common causes in the 20 cases with bilirubin encephalopathy.94 severe hyperbilirubinemia newborns were tested for uridine diphosphate glucuronosyl transferase 1A1(UGT1A1)*6 variant(rs4148323,c.211G>A,p.Arg71Gly),9 cases were 211 G to A homozygous variant,37 cases were 211 G to A heterozygous variant,and 48 cases were wild genotypes.CONCLUSION The main cause for severe hyperbilirubinemia and bilirubin encephalopathy in eastern Guangdong of China were the hemolytic disease of the newborns,G6PD deficiency and infection.UGT1A1 gene variant was also a high-risk factor for neonatal hyperbilirubinemia.Targeted prevention and treatment according to the etiology may reduce the occurrence of bilirubin encephalopathy and kernicterus.

The high incidence of acute hemolysis due to favism in Ahvaz,Iranclinical features and laboratory findings

Objective:To collect comprehensive information about the features of favic patients in Ahvaz (Capital of Khouzestan,Iran) and analyze the extent of the differences with their corresponding in other regions.Methods:A total of 103 patients with acute hemolysis admitted to pediatric division of Abouzar Hospital located in the city of Ahvaz,Iran during 21st of June 2008 to 20th of June 2009 were analyzed retrospectively.Results:95.14% of the patients had favism while 4.86% of them underwent hemolysis due to other reasons.These patients were male(68.93%) and female children(31.06%) admitted mostly during the spring season.The three main symptoms were urine discoloration,jaundice and vomiting.At the admission time,the main hematologic findings were as follows:G6PD sufficient status(45.63%),G6PD deficient status(54.36%) and hemoglobin concentration:2.5-11.8(mean±SD:6.45±2.12) g/dL.Conclusions:In conclusion,Ahvaz was determined as a black zone for favism in which the disease can be considered a life threatening health problem.Moreover,slight differences were observed in the three main symptoms compared with favic patients in other regions.

Neonatal pyknocytosis in a preterm dizygotic twin

Infantile pyknocytosis(IP) is a rare, self-limited neonatal haemolytic anaemia that may require multiple blood transfusions. Only a little more than 50 cases have been reported in the medical literature, and the great majority of them concerns term infants. The etiology of IP is not well understood; most likely it results from a transient extra-corpuscular factor, whose nature is unknown, transmitted from mother to child or, alternatively, from a deficiency of an anti-oxidative agent. We report the case of two preterm twins, one of which suffered from IP and developed severe anaemia at age 2 wk, while the other was unaffected. Although no specific agent was identified as the cause of anaemia and IP, we speculate that the transmission of an agent from mother to child was unlikely, as only twin one suffered from IP. Smelly greenish diarrhoea occurred just before the presentation of IP, suggesting that the same agent led to both the diarrhoea and the oxidative injury. Because IP may remain underdiagnosed, it should be considered in cases of early unexplained severe hemolytic anemia.

Blood groups, hemoglobin phenotypes and clinical disorders of consanguineous Yansi population

AIM:To study frequency of blood groups,prevalence of sickle-cell anemia trait and glucose-6-phosphate dehydrogenase deficiency(G6PD),among consanguineous Yansi tribe.METHODS:A total of 525 blood samples were collected,of which 256 among the Yansi population,and269 for the unrelated control group in the Bandunduprovince of Democratic Republic of Congo.Blood group antigens were determined in the following systems:ABO,Rh,Kell,Duffy,Kidd and MNS.Blood grouping and extended phenotype tests were performed according to standard immunohematological procedures.Spot tests and tandem mass spectrometry were used respectively for the assessment of G6PD and sickle-cell anemia trait.RESULTS:The frequency of ABO phenotypes conformed to the following order O>A>B>AB with notably 62.5%,23.8%,12.1%and 1.6%for the Yansi,and 54.6%,27.5%,14.1%and 3.7%for the unrelated control group,respectively(P=0.19).As for the Rh phenotypes,the most frequent were cc D.ee,cc D.Ee,Cc D.ee,corresponding to 71.5%,12.1%and 12.1%for the Yansi,and 70.6%,15.6%and 8.2%,for the unrelated control group(P=0.27).The frequency of MN and Ss phenotypes were statistically different between groups(P=0.0021 and P=0.0006).G6PD was observed in 11.3%of subjects in the Yansi group,and in 12.4%of controls(P=0.74).The sickle-cell anemia trait was present in 22.4%of Yansi subjects and 17.8%in the control group(P=0.24).Miscarriages and deaths in young age were more common among Yansi people.CONCLUSION:This study shows a significant difference in MNS blood group distribution between the Yansi tribe and a control population.The distribution of other blood groups and the prevalence of hemoglobinopathies did not differ in the Yansi tribe.