Glucose-6-phosphate dehydrogenase deficiency in neonates

Objective: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited deficiency that may be the cause of neonatal hyperbilirubinemia, as has been found in several countries and among widely different ethnic groups, especially in Mediterranean region. Our aim was to study the prevalence of G6PD deficiency in relation to neonatal jaundice.Methods : From March 1998 to April 2001 we studied 705 clinically icteric neonates who were admitted to Al-Zahra and Beheshti hospitals, two teaching hospitals in Isfahan, Iran. Laboratory investigations included determination of direct and indirect serum bilirubin concentrations, blood group typing, direct coomb’s test, hemoglobin, blood smear, reticulocyte count and G6PD level.Results: In only 53(7.5%) of cases G6PD deficiency was diagnosed. In all G6PD deficient neonates no evidence of other factors known to cause hyperbilirubinemia were detected. The sex distribution was 13(24.5%)females and 40(75.5%)males in the G6PD deficient group. The mean bilirubin level in G6PD deficient and G6PD normal groups were 22.26 +/-8.36 and 18.14 +/-3.85 mg/dl, respectively (p=0.001). Phototherapy was required in G6PD deficient and other icteric neonates with duration of 3.76 +/-1.93 and 3.13 +/-2.14 days, respectively (p=0.045). Twenty-seven of the 53(50.9%) G6PD deficient infants required exchange transfusion. None of them developed kernicterus.Conclusions: Since the prevalence of severe hyperbilirubinemia among our neonates was relatively high and about half of them required exchange transfusion, early detection of this enzymopathy regardless of sex and close surveillance of the affected newborns may be important in reducing the risk of severe hyperbilirubinemia and exchange transfusion.     

Glucose-6-phosphate dehydrogenase deficiency in neonatal indirect hyperbilirubinemia

The aim of this article is to investigate the prevalence of Glucose-6-phosphate dehydrogenase (G6PD) deficiency in neonatal hyperbilirubinemia and to compare the clinical presentation and course of G6PD-deficient and normal patients. This study included a total of 624 term neonates with indirect hyperbilirubinemia from March 2001 to September 2004. Birth weight, sex, weight at admission, serum bilirubin at admission, maximum bilirubin, phototherapy duration, duration of hospitalization and the need for exchange transfusion were recorded. Laboratory evaluations included blood group typing of mother and newborn, complete blood count, peripheral blood smear, serum total and direct bilirubin, direct coombs test, reticulocyte count, serum-free T4 and TSH, urine analysis, urinary reducing substance and erythrocyte G6PD level. The analysis of the results indicated that 24 neonates with indirect hyperbilirubinemia were G6PD-deficient. No statistically significant difference was detected between G6PD-deficient and normal groups in relation to the time of onset of jaundice, reticulocyte count, hematocrit level, phototherapy duration and duration of hospitalization. Serum bilirubin at admission, maximum serum bilirubin level and the need for exchange transfusion were higher in G6PD-deficient group. From this study our conclusion is that the G6PD deficiency is a common enzyme defect causing severe indirect hyperbilirubinemia which may result in kernicterus. Early neonatal screening programmes should be instituted in countries where the deficiency is prevalent.     

Glucose-6-phosphate dehydrogenase status and neonatal jaundice.

Neonatal jaundice and its relationship to glucose-6-phosphate dehydrogenase (G6PD) status of healthy, term Chinese infants was evaluated in 220 G6PD-deficient infants, 26 intermediate infants who were observed for 3 weeks, and 116 normal (control) infants. Each infant was free of isoimmunisation, cephalhaematomas, or contusions. The mode of labour, method of delivery, and type of feeds had no appreciable effect on daily bilirubin levels. "Elevated" physiological jaundice was associated with normal and G6PD-deficient status; there was no increased haemolysis. G6PD-deficient status was associated with jaundice significantly raised especially in the first week of life, and prolonged beyond that of the "elevated" physiological jaundice. Significantly increased though mild haemolysis was observed. Close surveillance is therefore required for G6PD-deficient infants at least for the first week of life, the period of increased risk. With G6PD-intermediate infants, only the usual measures for normal infants are required.     

Glucose-6-phosphate dehydrogenase deficiency and kernicterus of South-East anatolia

OBJECTIVE: We aimed to investigate the rate of kernicterus, and physical and laboratory examination findings in hyperbilirubinemic infants with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. MATERIALS AND METHODS: This study was carried out in the Dicle University Hospital Neonatal Intensive Care Unit between June 2005 and June 2006. Out of 56 male neonates who needed an exchange transfusion due to hyperbilirubinemia, 10 with G-6-PD deficiency were included in the study. Maternal age, gestational age, route of delivery, birth weight, age at the time of admission, and treatment and outcome were recorded. Laboratory investigations included determination of direct and indirect serum bilirubin concentrations, blood group typing, direct Coomb test, complete blood count, blood smear, thyroid-stimulating hormone, T4, C-reactive protein, urine analysis, and G-6-PD level. RESULTS: Out of 56 male neonates requiring exchange transfusion, 10 had G-6-PD deficiency (18%). In G-6-PD deficient neonates, other factors known to cause hyperbilirubinemia were excluded. The mean gestational age and the mean maternal age was 38.2+/-1.0 weeks and 31.3+/-5.9 years, respectively. The mean bilirubin level was 42.1+/-13.7 mg/dL. Four patients required a second exchange transfusions, and only 1 transfusion was sufficient for the remaining patients. Five patients (55%) developed kernicterus. CONCLUSIONS: Early detection of G-6-PD deficiency in the affected newborns may be important for reducing the risk of severe hyperbilirubinemia, kernicterus, and the need for exchange transfusion.     

Glucose-6-phosphate dehydrogenase activity in male premature and term neonates

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) activity is higher in term neonates than in adults. Some studies have suggested that activity may be even higher in preterm infants. OBJECTIVES: To determine if G6PD activity is higher in preterm than term neonates, and whether higher activity would interfere with diagnosis of G6PD deficiency in premature infants. METHODS: G6PD activity was determined in the first 48 hours after delivery in male premature, term, and near term infants. G6PD deficient neonates were separated, and the remaining premature infants compared with healthy, male, G6PD normal, near term and term neonates. RESULTS: Ninety four premature infants (mean (SD) gestational age 31.9 (3.8) weeks (range 23-36)) were studied. In four, G6PD activity was 0.8-1.8 U/g haemoglobin (Hb), which is clearly in the deficient range with no overlap into the normal range. G6PD activity in the remaining premature infants was significantly higher than in 24 near term and term neonates (gestational age > or = 37 weeks) (14.2 (4.6) v 12.0 (3.8) U/g Hb). Further analysis showed that significance was limited to those born between 29 and 32 weeks gestation, in which group G6PD activity was significantly higher than in those born before 29 weeks gestation, at 33-36 weeks gestation, and > or = 37 weeks gestation. CONCLUSIONS: G6PD activity is higher in premature infants born between 29 and 32 weeks gestation than in term neonates. This did not interfere with diagnosis of G6PD deficiency.     

Glucose-6-phosphate dehydrogenase enzyme activity in normal, hemizygote and heterozygote Kelantanese Malays

This prospective study was performed to quantify glucose-6-phosphate dehydrogenase (G6PD) enzyme activity in deficient males and female heterozygotes. The methods used in the study were the fluorescent spot test, G6PD enzyme electrophoresis on cellulose acetate and quantitative assays. Forty-seven children who had been detected as spot screen deficient at birth were rescreened. Their first degree relatives were also included in the study. The mean enzyme activity of deficient males was 0.74 iu/g Hb (s.d. +/- 0.8), of female heterozygotes was 6.5 iu/g Hb (s.d. +/- 3.2) and of normal males was 12.1 iu/g Hb (s.d. +/- 3.5). The mean activity in deficient males was 6.1% of normal males. Most (35 of 47) of these fell into class 2 in Beutler's classification of G6PD variants. This indicates a population which may be susceptible to favism. Female heterozygotes had an intermediate enzyme activity with a wide scatter. Using a cut off point of enzyme activity of below 9.0 iu/g Hb gave sensitivity and specificity of 87% and 84% in detecting female heterozygotes. This group could be defined more accurately by combining quantitative assays with family studies.     

Some observations on glutathione instability and glucose-6-phosphate dehydrogenase deficiency in infants and children having anaemia and jaundice

Summary The present study was conducted on 310 infants and children: 100 normal control cases, 80 cases of anaemia and 130 cases of jaundice. Erythrocytic reduced glutathione and glucose-6-phosphate dehydrogenase were estimated by Beutler’s and Brewer’s techniques respectively. In normal children the incidence of glutathione instability was 6 per cent. In cases of anaemia 11% presented with drug induced acute haemolytic crisis while the defect was present in 17.5% of cases. The glutathione instability was detected in 13.5% of cases of jaundice. Unstable glutathione with normal glucose-6-phosphate dehydrogenase was a common feature in all the groups but the converse was not true. There was a slight preponderance in males. The value of glutathione ranged from 47 to 125 mg. before incubation and 6.1–98 mg. % after incubation with a mean of 76 mg. % and 60 mg. % respectively in the control group. In the enzyme deficient cases, the values were significantly lower. From the Departments of Paediatrics and Pathology, S.N. medical College, Agra.     

Glucose-6-phosphate dehydrogenase deficiency-induced hemolysis in newly diagnosed diabetic monozygotic twins

A pair of monozygotic male twins are described who manifested hemolysis at the concurrent onset of diabetes type 1. Hemolysis appeared progressively following the correction of hyperglycemia and ketoacidosis (one twin). It was found to be related to unknown glucose 6-phosphate dehydrogenase (G-6-PD) deficiency. Other causes of hemolysis such as drugs or bacterial infection were excluded. The fall in glucose availability after the correction of hyperglycemia is proposed as a possible explanation for hemolysis.