浙江地区新生儿葡萄糖-6-磷酸脱氢酶缺乏症的遗传学分析

目的　分析浙江地区新生儿葡萄糖-6-磷酸脱氢酶（glucose-6-phosphate dehydrogenase，G6PD）缺乏症的基因突变特点，探讨其遗传多样性。方法　以2015年3月至2017年9月在浙江地区出生、经浙江省新生儿遗传代谢筛查中心G6PD缺乏症筛查发现的2242例患儿为对象，收集其新生儿筛查的G6PD活性值与剩余干滤纸血斑，并提取其血斑的基因组DNA。采用MassARRAY技术检测35个G6PD突变位点。采用SPSS 22.0软件统计分析基因型与G6PD活性的关系，P＜0.05为差异有统计学意义。结果　2163例检出突变，总检出率为96.47%，其中男性为96.51%（1995/2067），女性为96%（168/175）。共检出21种突变位点，44种变异基因型，其中男性半合子19型，女性杂合子14型，女性纯合子3型，女性复合杂合8型。95.93%的G6PD突变位于12、9、2、5外显子，其中c.1376G＞T、c.1388G＞A、c.1024C＞T、c.95A＞G、c.871G＞A、c.392G＞T占92.96%。c.1376G＞T、c.1388G＞A、c.1024C＞T、c.95A＞G四种基因型的G6PD活性差异有统计学意义（P＜0.0001）。结论　浙江地区G6PD缺乏症存在基因突变热点，c.1024 C＞T的突变频率具有明显地域特征，MassARRAY技术检测特定G6PD突变位点可推荐为G6PD缺乏症的二级筛查方法之一。     

Efficacy of phototherapy in neonatal hyperbilirubinaemia associated with glucose-6-phosphate dehydrogenase deficient status

The efficacy of phototherapy in a group of 427 infants with hyperbilirubinaemia associated with glucose-6-phosphate dehydrogenase (G6PD) deficiency and a comparable group of 3924 G6PD normal infants with non-haemolhtic hyperbilirubinaemia was evaluated. Phototherapy was highly effective in reducing bilirubin levels in both groups of infants, being significantly more effective in the group with normal G6PD status. Failure rate was very low (2.03/1000) in the group with normal G6PD status and nil in the G6PD deficient group. Bilirubin rebound after phototherapy was unremarkable with very few infants requiring a second exposure —4.68/1000 in the G6PD deficient group and 6.37/1000 in the G6PD normal group. All the babies tolerated phototherapy well. Phototherapy would therefore seem to be a simple and effective method for the management of severe jaundice associated with G6PD deficiency.     

Hereditary glucose-6-phosphate dehydrogenase deficiency in newborn infants]

Early diagnosis of the deficiency of glucose 6-phosphate dehydrogenase was made in examining 428 samples of funic blood from 230 boys and 198 girls. The normal level of the enzyme activity was established in red blood cells of the healthy newborn with regard to the national and sexual differences. The hereditary character of the deficiency of glucose 6-phosphate dehydrogenase was supported in 37 neonates by analyzing the pedigrees. The enzyme deficiency was associated with different forms of hemoglobinopathies: alpha- and beta-thalassemia, structurally abnormal hemoglobin S and methemoglobinemia. The considerable prevalence of the deficiency of glucose 6-phosphate dehydrogenase was revealed in Azerbaijan for the first time. The phenotypic frequency amounted to 8.64% whereas the gene one to 0.0623.     

Hyperbilirubinemia in healthy neonates with glucose-6-phosphate dehydrogenase deficiency

A cohort study was carried out to assess the association between glucose-6-phosphate dehydrogenase (G6PD) deficiency, diagnosed by quantitative enzyme assay, and neonatal hyperbilirubinemia, defined as serum total bilirubin >/=15 mg/dl, in the well-baby nursery of Chang Gung Children's Hospital. Among 42,110 inborn infants, 757 male (3.54%) and 326 female (1.57%) newborns were G6PD-deficient. Compared to the occurrence of hyperbilirubinemia in G6PD-normal newborns (1.41% in male, 1.44% in female) in the well-baby nursery, a significantly higher incidence was observed in both G6PD-deficient male (11.36%) and female (7.06%) newborns. Further analyses demonstrated that the enzyme activity of G6PD in G6PD-deficient male newborns with hyperbilirubinemia (1.56+/-1.37 U/g Hb) were significantly lower than the subjects without hyperbilirubinemia (2.01+/-1.7 U/g Hb). No significant difference was observed in G6PD-deficient female newborns with hyperbilirubinemia (6.91+/-2.76 U/g Hb) compared to those without hyperbilirubinemia (7.81+/-2.84 U/g Hb). These data suggest that the G6PD-deficient neonates are at increased risk for hyperbilirubinemia even in the nursery free from agents that can potentially cause hemolysis to G6PD-deficient red cells. The lower G6PD enzyme activity was associated with the neonatal hyperbilirubinemia in G6PD-deficient male neonates.     

Neonatal jaundice and glucose-6-phosphate dehydrogenase deficiency in Basrah

In a study on a group of 186 newborn babies presenting with jaundice, erythrocyte glucose-6-phosphate dehydrogenase (G6PD) deficiency was detected in 95 (51%) of the patients. The incidence of severe hyperbilirubinaemia appeared to be much greater in G6PD-deficient infants (46%) than in infants who did not have the red cell defect (15%). No change was found in this association when ABO incompatibility was excluded. Phototherapy did not reduce the need for exchange transfusion, which was necessary in 27 babies. Eight babies developed kernicterus and one died. Early detection of G6PD deficiency and close surveillance of the affected newborns may be important in reducing the risk of severe neonatal jaundice and kernicterus associated with G6PD deficiency in Basrah.     

Henna causes life threatening haemolysis in glucose-6-phosphate dehydrogenase deficiency.

Haemolytic crisis in glucose-6-phosphate dehydrogenase deficient individuals following topical application of henna occurred in four children: a female neonate (haemoglobin 50 g/l, serum bilirubin 700 micromol/l), who recovered after exchange transfusion; a male infant (haemoglobin 28 g/l) who died despite transfusion; and two preschool children (haemoglobin 40 and 41 g/l respectively).     

Molecular basis of glucose-6-phosphate dehydrogenase deficiency among Filipinos

BACKGROUND: Multiplex polymerase chain reaction (PCR) using multiple tandem forward primers and a common reverse primer (MPTP) was recently established as a comprehensive scanning system for mutations in X-linked recessive diseases. In this report, MPTP was tested to scan for mutations of the glucose-6-phosphate dehydrogenase (G6PD) gene. METHODS: Mutations in exon 11 of the G6PD gene were screened by MPTP in five unrelated Filipino cases with G6PD deficiency. RESULTS: Of the five patients, four screened positive for a mutation in the gene. Sequencing of the amplified products confirmed that three cases had a C-->T substitution at nucleotide (n.t.) 1360 (C1360T) resulting in an amino acid change of arginine to cysteine at position 454 and one had a silent single base substitution C-->T at nucleotide 1311. CONCLUSION: Our results document a C1360T mutation of the G6PD gene in three Filipino patients in the Philippines.     

Risk medications in case of glucose-6-phosphate dehydrogenase deficiency]

The best known morbid effect of glucosephosphate dehydrogenase (G-6PD) deficiency is hemolysis induced by oxidative drugs. When prescribing drugs for G-6PD deficient subjects, two points should be kept in mind: different genetic variants of G-6PD deficiency entail different susceptibility to the hemolytic risk from drugs; thus a drug found to be safe in some G-6PD deficient subjects may not be equally safe in others; the risk and severity of hemolysis is almost always dose-related. The purpose of this paper is to underline the main drugs that cannot be safely administrated to G-6PD deficient subjects. They can be separated in drugs that must be avoided by G-6PD deficient subjects (such as sulphonamides, quinolones, nitrofurantoin), and drugs that do not systematically precipitate hemolysis but must nevertheless be prescribed with caution.