Neonatal jaundice and molecular mutations in glucose-6-phosphate dehydrogenase deficient newborn infants

Molecular mutations of the glucose-6-phosphate dehydrogenase (G6PD) gene and clinical manifestations of neonatal jaundice in 112 male and 50 female Chinese neonates with G6PD deficiency were studied. In the 112 males, the nucleotide (nt) 1376 (G→T) mutation was the dominant type (50.0%), followed by nt 1388 (G→A) (16.1%), nt 493 (A→G) (8.0%), nt 1024 (C→T) (6.2%), nt 95 (A→G) (5.4%), nt 392 (G→T) (1.8%), nt 487 (G→A) (1.8%), nt 871 (G→A) (0.9%), and nt 1360 (C→T) (0.9%). The nt 871 variant has not been reported in Taiwan before. The occurrence rates for nt 1376, nt 1388, nt 493, nt 95, and nt 1024 mutations in the 50 females were 44.0%, 18.0%, 12.0%, 6.0%, and 6.0%, respectively. The type of G6PD mutation in 10 male and 7 female neonates has not been identified yet. Although G6PD deficient neonates had higher frequency of phototherapy than G6PD normal neonates in both sexes, a significant difference in the prevalence of hyperbilirubinemia (peak bilirubin ≥ 15.0 mg/dl) between G6PD deficient and normal neonates was found only in males. Further analysis showed that duration of phototherapy was longer in G6PD deficient male neonates than in the control group, while the outcome of phototherapy was better in subjects with non-nt 1376 mutations than subjects with the nt 1376 mutation. Most (78.3%) of the 23 G6PD deficient neonates who subsequently suffered from neonatal hyperbilirubinemia carried the nt 1376 mutation. The results of this study indicate that the nucleotide substitution at 1376 is the most common and important mutation for G6PD deficiency in Chinese neonates in Taiwan. © 1996 Wiley-Liss, Inc.     

Glucose-6-Phosphate Dehydrogenase Deficiency and Neonatal Jaundice in Jamaica

Glucose-6-phosphate dehydrogenase (G6PD) deficiency was detected in 16 (69.6%) of a group of 23 neonates who had unexplained moderate or severe jaundice. This proportion is significantly more than the 9.4% observed or the 22.2% expected in Jamaican neonates who are not moderately or severely jaundiced (P less than 0.003), and significantly more than the 12.6% observed or the 21.0% expected in older Jamaican children and adults (P less than 0.003). Phenobarbitone therapy and phototherapy reduced the need for exchange transfusion but this was necessary in eight patients. Two babies developed kernicterus and one died. On the other hand, only two of 21 neonates who were identified as G6PD deficient at birth subsequently became moderately or severely jaundiced, and this could be attributed to other causes in both cases. These findings indicate that apparently spontaneous neonatal jaundice is important in infants who have the G6PD A--enzyme. However, the jaundice is probably precipitated by unknown factors to which the G6PD deficient neonate is more susceptible than the infant who is not G6PD deficient. THere is also a slightly increased incidence of G6PD deficiency in neonates who develop jaundice because of ABO or Rh(D) iso-immune disease, infection or prematurity.     

Change in serum and biliary esterified bile acids in patients with extrahepatic cholestasis during percutaneous transhepatic cholangiodrainage

Eighteen patients with total extrahepatic cholestasis undergoing PTCD were classified into three groups, depending on the bilirubin decrease rate at two weeks after PTCD. Serum and biliary esterified bile acids in each group were measured before PTCD and at 24 hours, 48 hours, 1 week, and 2 weeks after PTCD. Bile acids were measured by Okuyama's methods (HPLC), and esterified bile acids were calculated from the difference between samples treated with sulfatase or beta-glucuronidase for enzymatic hydrolysis and untreated samples measured at the same time. The following results were obtained. The percentages of biliary esterified bile acids in total bile acids were as follows: before PTCD, in the fair improvement group, sulfate (S) = 6.4 +/- 4.6% (mean +/- S.D.), glucuronide (G) = 11.7 +/- 9.0%; in the poor improvement group, S = 2.8 +/- 1.6%, G = 1.0 +/- 0.9% and at 24 hours after PTCD, in the fair group, S = 9.1 +/- 7.5%, G = 7.5 +/- 4.3%; in the poor group, S = 2.9 +/- 2.4%, G = 1.7 +/- 1.1%. The percentages of esterified bile acids in the fair group were higher than in the poor group, and significant differences were noted in G (p less than 0.05). Thus PTCD is expected to reduce jaundice in cases with high percentages of biliary esterified bile acids before and shortly after PTCD.     

Red cell metabolism and severe neonatal jaundice in West Malaysia.

A study was carried out of 332 babies suffering from severe neonatal jaundice who were admitted to the General Hospital, Kuala Lumpar, Malaysia. Of the 332 neonates, 51 were premature and 281 were full-term babies, 178 (110 Chinese, 58 Malay, 9 Indian and 1 European-Pakistani) had bilirubin levels of 20 mg% or higher, requiring exchange blood transfusion. Of the Chinese neonates, 23 (20.9%) had G6PD deficiency, 9 (8.2%) had Hb Bart's and 2 (1.8%) had an abnormal haemoglobin, one Hb Q and one fetal variant. Among the Malay infants, 10 (17.2%) had G6PD deficiency, 7 (12.1%) had Hb Bart's and 10 (17.2%) had abnormal haemoglobins (four had Hb E trait, one had Hb K and Bart's in addition to Hb E, three had Hb CoSp with Hb Bart's, one had Hb Q and one Hb Tak). One of the nine Indian neonates had G6PD deficiency and one had Hb S trait. The one European-Pakistani baby was a carrier of Hb D Punjab. In addition to G6PD deficiency, abnormal haemoglobins seem to have contributed to the high incidence of severe neonatal jaundice in Malaysia. The mean activities of GP, GR and GR after stimulation with FAD were higher, while the mean activity of PK and mean level of reduced glutathione were lower than in normal cord bloods. The percent increase of GR after FAD stimulation was significantly lower; fewer in this group had increases above 20% than in normal cord blood. The possible significance of the findings is discussed.     

The prevalence of G6PD deficiency in blood transfusion recipients

G6PD deficiency is the most common metabolic disorder of red blood cells, involving about 35 million people worldwide. Tropical and subtropical regions in the eastern hemisphere have the highest prevalence, up to 35% in some areas. The prevalence varies in different parts of the world. According to WHO, there is a 10-14.9% prevalence of G6PD deficiency in Iran. With this high prevalence, blood products are not still checked for G6PD deficiency. So, they may be used for transfusion in neonates with jaundice or for patients using oxidants. In this cross-sectional study, we have observed the effects of using this kind of blood in patients receiving blood in the Pediatric and Neonatology Departments of Imam Sajjad's Hospital in Yasuj. Samples were taken from 261 blood bags used for transfusion or exchange, and examined by spot fluorescence for G6PD deficiency. All of the patients receiving blood were examined for hemoglobin, hematocrit, and bilirubin before and after transfusion. They were also examined for hemoglobinuria, factors involved in hemolysis due to G6PD deficiency, and oxidants. Results: From the 261 blood transfusions, 37(14.17%) blood bags had G6PD deficiency. About 81% of these transfusion recipients had at least one risk factor for hemolysis. The complications associated with receiving these red cells were: insufficient rise in hemoglobin (55.9%), hemoglobinuria (35.3%) and rise in bilirubin (8.8%), which were significantly higher than the control group. Conclusion: Considering the high prevalence and complications of transfusing G6PD deficient blood to high risk patients, it is recommended that in the form used for requesting blood products, there should be a place for checking G6PD enzyme so that the physician requesting blood could request the test to be done, depending on the risk factors.     

G6PD enzyme activity in normal term Malaysian neonates and adults using a OSMMR2000-D kit with Hb normalization

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the commonest causes of neonatal jaundice in Malaysia. Screening of cord blood for G6PD deficiency by the semiquantitative fluorescent spot test (FST) is performed in Malaysia but this test can miss cases of partial G6PD deficiency. The OSMMR-D kit assay measures G6PD activity and hemoglobin (Hb) concentration, allowing direct expression of results in U/gHb. We evaluated this method and established the normal range for G6PD activity in normal term neonates and adults. EDTA blood from 94 neonates and 295 adults (age 15-59 years old) with normal Hb and FST were selected. The normal means for G6PD activity for neonates and adults were 12.43 +/- 2.28 U/gHb and 9.21 +/- 2.6 U/gHb, respectively; the reference ranges for normal G6PD activity in neonates and adults were 10.15-14.71 U/gHb and 6.61-11.81 U/gHb respectively. There were no significant differences in mean normal G6PD activity between the Malays and Chinese racial groups or between genders. The upper and lower limit cut-off points for partial deficiency in neonates were 7.4 U/gHb (60% of the normal mean) and 2.5 U/gHb (20% of the normal mean), respectively. For adults, the upper and lower limit cut-off points for partial deficiency in adults were 5.52 U/gHb (60% of the normal mean) and 1.84 U/gHb (20% of the normal mean), respectively. The quantitation of G6PD enzymes using this OSMMR-D kit with Hb normalization was simple since the Hb was analyzed simultaneously and the results were reproducible with a CV of less than 5%.     

Comparison of serum copper, magnesium, zinc and calcium levels between G6PD deficient and normal Chinese adults

Minerals are important for normal hematopoiesis and may play a role in acute hemolytic anemia induced by G6PD deficiency. To compare serum magnesium, copper, zinc and calcium levels between G6PD deficiency and normal control adults, we investigated 69 G6PD deficient (28 male, 41 female) and 61 age- matched G6PD normal adults (26 male, 35 female). Serum magnesium, copper, zinc and calcium levels were determined by atomic absorbance spectrometry. Our results revealed that male adults with G6PD deficiency had significantly higher serum copper and magnesium levels than those of the control group (P < 0.01, < 0.05, respectively). In G6PD normal adults, serum copper levels were significantly lower in males than in females (P < 0.01). In the group of G6PD deficiency adults, serum copper levels in males (103.0 +/- 10.4 ug/dL) were significantly lower than those in females (139.0 +/- 34.3 ug/dL) (P < 0.01). Serum magnesium values and zinc values in males (2.42 +/- 0.38 mEq/L and 102.2 +/- 26.5 ug/dL) were significantly higher than those in females (2.07 +/- 0.20 mEq/L and 87.0 +/- 14.9 ug/dL) (P all < 0.01). Female adults with G6PD deficiency had significantly higher serum calcium levels and lower magnesium levels than those of the control group (P all < 0.01). The significantly higher levels of serum copper and magnesium in G6PD deficient male adults may play some role concerning red blood cells in resistance to plasmodium falciparum.     

The prevalence of G6PD deficiency in blood transfusion recipients

G6PD deficiency is the most common metabolic disorder of red blood cells, involving about 35 million people worldwide. Tropical and subtropical regions in the eastern hemisphere have the highest prevalence, up to 35% in some areas. The prevalence varies in different parts of the world. According to WHO, there is a 10–14.9% prevalence of G6PD deficiency in Iran. With this high prevalence, blood products are not still checked for G6PD deficiency. So, they may be used for transfusion in neonates with jaundice or for patients using oxidants.

In this cross-sectional study, we have observed the effects of using this kind of blood in patients receiving blood in the Pediatric and Neonatology Departments of Imam Sajjad's Hospital in Yasuj. Samples were taken from 261 blood bags used for transfusion or exchange, and examined by spot fluorescence for G6PD deficiency. All of the patients receiving blood were examined for hemoglobin, hematocrit, and bilirubin before and after transfusion. They were also examined for hemoglobinuria, factors involved in hemolysis due to G6PD deficiency, and oxidants.

Results: From the 261 blood transfusions, 37 (14.17%) blood bags had G6PD deficiency. About 81 % of these transfusion recipients had at least one risk factor for hemolysis. The complications associated with receiving these red cells were: insufficient rise in hemoglobin (55.9%), hemoglobinuria (35.3%) and rise in bilirubin (8.8%), which were significantly higher than the control group.

Conclusion: Considering the high prevalence and complications of transfusing G6PD deficient blood to high risk patients, it is recommended that in the form used for requesting blood products, there should be a place for checking G6PD enzyme so that the physician requesting blood could request the test to be done, depending on the risk factors.     

Glucose-6-phosphate dehydrogenase deficiency is associated with increased initial clinical severity of acute viral hepatitis A

BACKGROUND AND AIM: In glucose-6-phosphate dehydrogenase (G6PD) deficiency, the enzyme is deficient in liver cells as well as in erythrocytes. It has been suggested that this may be associated with a more severe clinical presentation of acute viral hepatitis A. The aim of this study is to determine the severity of liver disease in patients with viral hepatitis and G6PD deficiency. METHODS: Eighteen patients with diagnosed G6PD deficiency and acute hepatitis A were compared with 18 matched control patients with hepatitis A in a university hospital for liver disease severity and clinical outcome. RESULTS: Two of 18 patients with G6PD deficiency had neurological deterioration. Patients with G6PD deficiency had a mean peak prothrombin time (PT) that was significantly prolonged as compared with the control group (15.5 +/- 3.7 vs 12.9 +/- 2.0 s, respectively, P < 0.02), and a significantly higher proportion had an abnormal PT (PT > 13.3 s): 61 versus 11% (P < 0.0001). Hemolysis occurred in 44% of the G6PD deficiency patients. Total and direct bilirubin were significantly higher in all patients with G6PD deficiency, including patients without hemolysis. There was no significant difference in liver enzyme levels between the two groups. Patients with G6PD deficiency had a longer average hospital stay (9.5 +/- 4.8 vs 3.4 +/- 0.8 days, respectively, P < 0.001). There was no difference in the final clinical outcome between the two groups, and recovery of liver function was seen in all patients. CONCLUSIONS: Glucose-6-phosphate dehydrogenase deficiency in patients with hepatitis A causes a more severe initial clinical presentation, but does not alter the final clinical outcome.     

Phototherapy induces oxidative stress in premature neonates.

BACKGROUND: Phototherapy is a widely used treatment modality for unconjugated hyperbilirubinemia in newborn infants. We investigated whether phototherapy leads to oxidative stress in preterm newborns. METHODS: Thiobarbituric acid reactive substances (TBRS) were measured in the blood of 30 icteric preterm newborn infants, before and after 96 hours of continuous blue-light phototherapy. The mean (SD) gestational age was 32.3 (1.8) weeks and birth weight was 1606 (288) grams. The mean age of onset of jaundice was 44 (21.4) hours. RESULTS: The maximum total serum bilirubin was 14.6 (1.5) mg/dL and that after phototherapy was 8.6 (0.8) mg/dL. TBRS levels after phototherapy were significantly higher than those before phototherapy (11.4 [2.9] vs. 6.9 [2.2] nmol/L; [p<0.001]). CONCLUSION: Blue-light phototherapy induces an oxidative stress in preterm neonates.     

Mild hemolysis in a girl with G6PD Sumaré (class I variant) associated with G6PD A-

In the present study we describe the clinical and laboratory features of a female child, a compound heterozygote for glucose-6-phosphate dehydrogenase (G6PD) Sumaré (1292T-->G) and African variants (202G-->A). G6PD Sumaré is a variant causing chronic nonspherocytic hemolytic anemia. The child had neonatal jaundice 2 days after birth and needed phototherapy for 8 days. Since then, she has not had episodes of dark urine or new episodes of jaundice. She has not had hemolytic crises in spite of five respiratory infections and antibiotics administration. Laboratory data showed a reticulocytosis (5.6%) without anemia and serum unconjugated bilirubin at the upper limit of the normalcy. No hemoglobin and hemosiderin in the urine were detected. G6PD activity at 37 degrees C was 1.15 UI/g Hb and G6PD cellulose acetate electrophoresis at pH 9.0 revealed two bands, in equal amounts, with normal and faster migration, respectively. She was homozygous for the normal (TA)6(TA)6 repeat in the UGT1A1 promoter. We conclude that the association of G6PD Sumaré and G6PD A- gave rise to a very mild chronic hemolysis, and the red cell population containing G6PD A- is probably enough to protect against severe chronic hemolysis.     

Molecular characterization of glucose-6-phosphate dehydrogenase deficiency in Chinese infants with or without severe neonatal hyperbilirubinaemia

Summary. To characterize mutations in the glucose-6-phosphate dehydrogenase (G6PD) gene in Chinese infants, we studied 213 G6PD-deficient infants without blood exchange transfusion (BET) therapy, and 34 patients who required BET therapy for their severe hyperbilirubinaemia after birth. Nine different point mutations were characterized in all infants. Of these mutations, the G to T substitution at cDNA nucleotide (nt) 1376, which accounts for the mutations in 131 (53.0%) neonates, followed by G to A substitution at nt 1388 in 18 (10.5%) infants, A to G substitution at nt 493 in 17 (6.9%) infants, A to G substitution at nt 95 in 10 (4.1%) infants, C to T substitution at nt 1024 in six (2.4%) infants, and G to T substitution at nt 392 in three (1.2%) infants, G to A substitution at nt 487 in two (0.8%) infants, C to T substitution at nt 1360 in two (0.8%) infants and C to T substitution at nt 592 in two (0.8%) infants. Mutations in 48 (19.5%) G6PD-deficient infants were not characterized. Most (64.7%) mutations in the G6PD-deficient infants who required BET therapy after birth result from a G to T substitution at nt 1376. The enzyme activity of G6PD deficient infants who required BET therapy is significantly lower than for those who did not, even in a group with the same variant (as in 1376 mutation). Severe neonatal jaundice requiring BET therapy can take place with the majority of variants encountered in this area.     

Content of reduced glutathione and consequences in recipients of glucose-6-phosphate dehydrogenase deficient red blood cells

The red blood cell glucose-6-phosphate dehydrogenase (G6PD) activity of every donor was examined with automatic enzyme-coupled method. The technique of molecular biology was applied to determine the DNA mutations for the 97 donors with undetectable G6PD activity. The concentration of reduced glutathione (GSH) in the stored RBC of the 97 G6PD-deficient donors and 124 normal donors was determined with the technique of high performance liquid chromatography. Routine blood counts, bilirubin and haptoglobin levels were used to evaluate posttransfusional hemolysis for the 48 adult patients transfused with 1 U G6PD deficient and 1 U normal RBC. Most (88, 90.7%) of the 97 donors were confirmed to be G6PD deficient at the DNA level. At each age interval of storage, the GSH concentration of G6PD-deficient RBC was significantly different from that of normal RBC. The total average value of GSH (μmol/gHb) was 2.52 ± 0.95 (mean ± 1 standard deviation) vs. 3.74 ± 1.43 (P < 0.001). Hemoglobin, hematocrit, bilirubin, and haptoglobin levels in the patients receiving G6PD-deficient RBC were not statistically different from those in the recipients of normal RBC; even though the age of stored blood was 26–35 days. Within the same group of patients, the results of bilirubin and haptoglobin were not significantly changed before and after transfusion. The results of this study show that the GSH concentration in the stored blood of G6PD deficient donors was 67% of that in the normal donors. However, hemolysis does not occur in adult patients transfused with 1 U G6PD-deficient RBC. It seems unnecessary to screen G6PD activity for donors of adult recipients in Taiwan. Am. J. Hematol. 57:187–192, 1998. © 1998 Wiley-Liss, Inc.     

A simple, rapid fluorometric assay for the determination of glucose 6-phosphate dehydrogenase activity in dried blood spot specimens

Glucose 6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy of human beings and is the most common cause of jaundice and acute hemolytic anemia in South East Asia. The deficiency causes acute hemolytic anemia following ingestion of 6-amino quinoline antimalarials, phenacetin, and other substances. The rapid identification of infants or patients with this deficiency would help to prevent their exposure to these substances and subsequent risk to health. The assay is relatively simple. A 3mm punch from a dried blood spot sample is placed in a well of a black fluorescent microtiter plate containing calibrators and controls in duplicate. 100 microl of reagent is added and the sample is allowed to react for 30 minutes at ambient temperature after which 200 microl of stop reagent is added. The plate may be read immediately or up to one hour in a fluorescent reader (ex 355 nm: em 460 nm). Glutathione. ascorbate and bilirubin do not affect the assay. hemoglobin does quench the fluorescence by about 1.1 fluorescence units/g/dHb. This would not cause any false negatives and deficients would not be missed. G6PD activity in whole blood normal samples was examined at -20, 6 and 37 degrees C over 14 days. The samples lost about 20% activity after 48 hours and 31% by the end of 14 days. The samples stored at -20 degrees C and 6 degrees C remained relatively stable over this period. In a preliminary study eight diagnosed G6PD deficient samples had a mean value of 2.0 U/gHb (range 0.8 to 4.4) and fell within 3 SD units of the mean. Forty one normal samples had a mean of 6.6 micromol/min/gHb. Only one sample with a low hemoglobin level fell outside of 3 SD units of the mean. The Wallac assay was compared to the Sigma G6PD assay and although the values appeared lower at normal levels, the deficient samples compared well.     

Effects of variant UDP-glucuronosyltransferase 1A1 gene, glucose-6-phosphate dehydrogenase deficiency and thalassemia on cholelithiasis

AIM: To test the hypothesis that the variant UDPglucuronosyltransferase 1A1 (UGT1A1) gene, glucose-6-phosphate dehydrogenase (G6PD) deficiency, and thalassemia influence bilirubin metabolism and play a role in the development of cholelithiasis. METHODS: A total of 372 Taiwan Chinese with cholelithiasis who had undergone cholecystectomy and 293 healthy individuals were divided into case and control groups, respectively. PCR and restriction fragment length polymorphism were used to analyze the promoter area and nucleotides 211, 686, 1 091, and 1 456 of the UGT1A1 gene for all subjects and the gene variants for thalassemia and G6PD deficiency. RESULTS: Variation frequencies for the cholelithiasis patients were 16.1%, 25.8%, 5.4%, and 4.3% for A(TA)_6 TAA/A(TA)_7 TAA (6/7), heterozygosity within the coding region, compound heterozygosity, and homozygosity of the UGT1A1 gene, respectively. Comparing the case and control groups, a statistically significant difference in frequency was demonstrated for the homozygous variation of the UGT1A1 gene (P=0.012, x~2 test), but not for the other variations. Further, no difference was demonstrated in a between-group comparison of the incidence of G6PD deficiency and thalassemia (2.7% vs 2.4% and 5.1% vs 5.1%, respectively). The bilirubin levels for the cholelithiasis patients with the homozygous variant-UGT1A1 gene were significantly different from the control analog (18.0±6.5 and 12.7±2.9μmol/L, respectively; P<0.001, Student's ttest). CONCLUSION: Our results show that the homozygous variation in the UGT1A1 gene is a risk factor for the development of cholelithiasis in Taiwan Chinese.     

Change in serum and biliary esterified bile acids in patients with extrahepatic cholestasis during percutaneous transhepatic cholangiodrainage

Eighteen patients with total extrahepatic cholestasis undergoing PTCD were classified into three groups, depending on the bilirubin decrease rate at two weeks after PTCD. Serum and biliary esterified bile acids in each group were measured before PTCD and at 24 hours, 48 hours, 1 week, and 2 weeks after PTCD. Bile acids were measured by Okuyama’s methods (HPLC), and esterified bile acids were calculated from the difference between samples treated with sulfatase or β-glucuronidase for enzymatic hydrolysis and untreated samples measured at the same time. The following results were obtained. The percentages of biliary esterified bile acids in total bile acids were as follows: before PTCD, in the fair improvement group, sulfate (S) = 6.4 ± 4.6 % (mean ± S.D.), glucuronide (G) = 11.7 ± 9.0 % ; in the poor improvement group, S = 2.8 ± 1.6 %, G = 1.0 ± 0.9 % and at 24 hours after PTCD, in the fair group, S = 9.1 ± 7.5 %, G = 7.5 ± 4.3 % ; in the poor group, S = 2.9 ± 2.4 %, G =1.7 ± 1.1 %. The percentages of esterified bile acids in the fair group were higher than in the poor group, and significant differences were noted in G (p<0.05). Thus PTCD is expected to reduce jaundice in cases with high percentages of biliary esterified bile acids before and shortly after PTCD.     

Semiquantitative screening test for G6PD deficiency detects severe deficiency but misses a substantial proportion of partially-deficient females

Neonatal screening for G6PD deficiency has long been established in many countries. The aim of the study was to determine whether the routine semiquantitative fluorescent spot test could detect all cases of G6PD deficiency, including those cases with partial deficiency (residual red cell G6PD activity between 20-60% of normal). We compared the results of G6PD screening by the semiquantitative fluorescent spot test and quantitative G6PD activity assay on a group of 976 neonates and 67 known female heterozygotes. The values for mean G6PD activity of G6PD-normal neonates and 293 healthy adult females were determined. There was no significant difference in the mean normal G6PD activity between the two racial groups in the neonates (669 Malays, 307 Chinese) and in the 293 healthy adult females (150 Malays, 143 Chinese) group. The values for the upper limits of total deficiency (20% of normal residual activity) for neonates and adult females were 2.92 U/gHb and 1.54 U/gHb, respectively. The upper limits of partial deficiency (60% of normal residual activity) were 8.7 U/gHb and 4.6 U/gHb respectively. The prevalence of G6PD deficiency among the male neonates was 5.1% (26) by both the fluorescent spot test and the enzyme assay method. The G6PD activity levels of all 26 cases of G6PD-deficient male neonates were < 20% normal (severe enzyme deficiency). In the female neonate group, the frequency of G6PD deficiency was 1.3% (6 of 472) by the fluorescent spot test and 9.35% (44 of 472) by enzyme assay. The 6 cases diagnosed as deficient by the fluorescent spot test showed severe enzyme deficiency (< 2.92 U/gHb). The remaining 38 female neonates had partial enzyme deficiency and all were misdiagnosed as normal by the fluorescent spot test. In the female heterozygote group, G6PD deficiency was diagnosed in 53% (35 of 67) by enzyme assay and in 7.5% (4 of 67) of cases by the fluorescent spot test. The 4 cases detected by fluorescent spot test had severe enzyme deficiency (<1.6 U/gHb). The remaining 31 (46.3%) cases, diagnosed as normal by fluorescent spot test, showed partial G6PD deficiency. In conclusion, we found that the semiquantitative fluorescent spot test could only diagnose cases of total G6PD deficiency and misclassified the partially-deficient cases as normal. In this study, the overall prevalence of G6PD deficiency was 3.28% by the semiquantitative fluorescent spot test and 7.17% by enzyme assay. This means that 3.9% of G6PD-deficient neonates were missed by the routine fluorescent spot test and they were found to be exclusively females. This study demonstrates a need to use a method that can correctly classify female heterozygotes with partial G6PD deficiency. The clinical implication is that these individuals may be at risk of the hemolytic complication of G6PD deficiency.     

葡萄糖-6-磷酸脱氢酶缺乏症患者心脏外科围手术期观察

目的 观察葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症患者心脏体外循环围手术期治疗方法.方法 以2005年1月至2010年12月间在广西桂林医学院附属医院中进行心脏手术的10例G6PD缺乏症确诊患者作为病例组观察对象.同期选取性别、年龄、体质量、所患心脏手术疾病相匹配的20例非G6PD缺乏症患者作为对照组观察对象.病例组患者围手术期治疗措施集中于避免药物引起的急性溶血反应,减少手术应激,采用浅低温体外循环,加强血液保护等.观察指标包括患者围手术期呼吸机辅助时间、尿量、胸管引流量、输红细胞悬液量、输血浆量、术后第2天血红蛋白和血总胆红素水平,重症监护病房(ICU)停留时间等.结果 病例组呼吸机辅助时间[(8.6±5.7)h]、尿量[(1950±490)ml]、胸管引流量[(260±l20)ml]、输红细胞悬液量[(1.8±1.2)U]、输血浆量[(80±50)ml]、术后第2天血红蛋白[(99±12) g/L]和总胆红素水平[(27±11)μmol/L]与对照组比较[(9.3±4.5)h、(2100±670)ml、(253±146)ml、(1.3±1.0)U、(120±50)ml、(96±25)g/L、(24±8)μmol/L],差异均无统计学意义(t值分别为0.978、2.032、1.257、0.891、2.182、2.271、1.329,P均＞0.05),但病例组ICU停留时间[(2.6±0.6)d]较对照组[(1.8±1.5)d]明显增长(t=2.704,P＜ 0.05).结论 G6PD缺乏症患者心脏体外循环手术时,加强围手术期处理效果较好.     

Neonatal hyperbilirubinaemia in heterozygous giucose-6-phosphate dehydrogenase deficient females

S ummary . Glucose-6-phosphate dehydrogenase (G6PD, D-glucose 6-phosphate: NADP oxidoreductase, E.C. 1.1.1.49) activity and the percentage of G6PD deficient erythrocytes was determined in 50 girls heterozygous for G6PD deficiency, 25 of whom had had hyperbilirubinaemia at birth and 25 who had normal bilirubin levels. The enzymatic activity was 2 32 ±0·87 l.U./g Hb in the first group and 3·31 ±0·92 l.U./g Hb in the second group. The percentage of G6PD deficient erythrocytes was 54.1 ±15.3 and 65.3 ±0.87, respectively. The level of enzymatic activity exceeded 4 I.U./g Hb and the percentage of G6PD deficient cells fell below 40% in only one of the subjects who had developed hyperbilirubinaemia. Levels of enzymatic activity below 4 I.U./g Hb, or percentages of G6PD deficient erythrocytes higher than 40% can therefore be considered to be associated with a high risk of developing neonatal hyperbilirubinaemia. In our opinion, these babies should receive prophylactic treatment with phenobarbital, as do G6PD deficient Mediterranean males.     

Glucose-6-phosphate dehydrogenase deficiency,the UDP-glucuronosyl transferase 1A1 gene,and neonatal hyperbilirubinemia

BACKGROUND & AIMS: Coinheritance of the A(TA)7TAA promoter variant in the uridine 5'-diphosphate-glucuronosyl transferase 1A1 (UGT1A1) gene and glucose-6-phosphate dehydrogenase (G6PD) deficiency is crucial to hyperbilirubinemia in white male neonates. A variation rate of 29.3% was determined within the coding region of the UGT1A1 gene in Taiwanese subjects, suggesting the hypothesis that this variation may influence incidence of hyperbilirubinemia in male neonates with G6PD deficiency. METHODS: The full sequence of the UGT1A1 gene was identified for 212 G6PD-deficient and 232 control male neonates by using polymerase chain reaction (PCR). RESULTS: Both study and control groups were divided into 5 subgroups according to their UGT1A1 genotypes. Most subjects carried G to A variation at nucleotide 211 for both genotypes of heterozygous variation within coding region and homozygous variation. No significant differences were noted for the frequencies of the 5 UGT1A1 genotypes, gestation age, and birth weight comparing the G6PD-deficient and control groups. The incidence of hyperbilirubinemia, however, was significantly higher for the study group than for the controls. This difference was noted only for the subgroup bearing the homozygous variant of the UGT1A1 gene. In the subgroup of homozygous variation, the serum bilirubin value was significantly higher for G6PD-deficient neonates than for controls. All 11 G6PD-deficient neonates with the homozygous 211 G to A variation suffered from hyperbilirubinemia. CONCLUSIONS: The results indicate that carriage of the homozygous 211 G to A variation within the coding region in the UGT1A1 gene is an additive risk factor for neonatal hyperbilirubinemia in G6PD-deficient Taiwanese male neonates.