Screening and prevention of neonatal glucose 6-phosphate dehydrogenase deficiency in Guangzhou, China.

We aimed to summarize the results of screening protocol and prevention of neonatal glucose 6-phosphate dehydrogenase (G6PD) deficiency during a 22-year-long period to provide a basis of reference for the screening of this disease. About 1,705,569 newborn subjects in Guangzhou City were screened for this deficiency. Specimens were collected according to the conventional method of specimen acquisition for "newborn dried bloodspot screening", preserved, and inspected. The specimens were studied with fluorescent spot test and quantitative fluorescence assay. Diagnosis was performed using the modified NBTG6PD/6PGD ratio method. Bloodspot filter paper specimens were sent to the laboratory within 24 h via EMS Express, and the G6PD test was performed on the same day. The G6PD deficiency-positive rate was 4.2% in the samples screened using the fluorescent spot test, while it was 5% in case of the quantitative fluorescence assay. Neonatal screening for G6PD deficiency for 11,437 cases (6117 boys and 5320 girls) showed positive results in 481 cases. About 420 cases (318 boys and 102 girls) of G6PD deficiency were confirmed with the modified Duchenne NBT ratio method. The total detection rate was 3.7:5.2% for boys and 1.9% for girls. Quantitative fluorescence assay improved the sensitivity and detection rate. Accelerating the speed of sample delivery by using Internet network systems and ensuring online availability of screening results can aid the screening and diagnosis of this deficiency within 1 week of birth.

Newborn screening.

Screening newborns for inherited disorders provides an opportunity for pre-symptomatic identification and early intervention to prevent or mitigate morbidity and mortality associated with these conditions. Since the introduction of newborn screening in 1962 to screen for phenylketonuria, technological advances have enabled the screening panel to expand substantially so that it now includes more than 50 disorders. Newborn screening will continue to evolve,, and deployment of improved methodologies and incorporation of additional disorders are expected. This article provides an overview of the current state of newborn screening, and describes the disorders detectable, the methodologies employed, and the challenges involved in analyses of specimens obtained from newborns.

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.

Frequency of haemoglobinopathies and glucose-6-phosphate dehydrogenase deficiency in Basra.

Basra, southern Iraq, was mapped for haemoglobinopathies and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Of 1064 couples aged 14-60 years recruited from the Public Health Laboratory, 49 had beta-thalassaemia trait, 69 had sickle-cell trait, 2 had haemoglobin D trait, 2 had haemoglobin C trait and 1 had high persistent fetal haemoglobin. Carriers of major beta-globin disorders comprised 11.48%. G6PD deficiency was detected in 133 individuals (12.5%). Only 10 couples (0.94%) were at risk of having children affected with either sickle-cell disease or beta-thalassaemia major. These defects constitute a real health problem and necessitate a management plan and public health education for early diagnosis and therapy.

Student screening for inherited blood disorders in Bahrain.

In Bahrain and neighbouring countries inherited disorders of haemoglobin, i.e. sickle-cell disease, thalassaemias and glucose-6-phosphate dehydrogenase (G6PD) deficiency, are common. As part of the National Student Screening Project to determine the prevalence of genetic blood disorders and raise awareness among young Bahrainis, we screened 11th-grade students from 38 schools (5685 students), organized lectures and distributed information about these disorders. Haemoglobin electrophoresis, high performance liquid chromatography, blood grouping and G6PD deficiency testing were performed. Prevalences were: 1.2% sickle-cell disease; 13.8% sickle-cell trait; 0.09% beta-thalassaemia; 2.9% beta-thalassaemia trait; 23.2% G6PD deficiency; 1.9% G6PD deficiency carrier. Health education, carrier screening and premarital counselling remain the best ways to reduce disease incidence with potentially significant financial savings and social and health benefits.

Glucose-6-phosphate dehydrogenase deficiency in blood donors: screening by micromethaemoglobin reduction test.

500 blood donors were screened for G6PD deeiciency using micromethaemoglobin reduction (microMRT) test. Most of the blood donors were young adult males (95.8%). The overall incidence of G6PD deficiency was found to be 0.8%. There, was apparently decreased frequency of G6PD deficient blood donors with increasing age, and no relation could be ascertained between G6PD) deficiency and blood groups.

Adequacy and pitfalls of G6PD deficiency counseling in Hong Kong.

Glucose-6-Phosphate-Dehydrogenase (G6PD) deficiency is common in Hong Kong with an incidence of 4.5% in male and 0.36% in female (Lo et al. 1996).The Neonatal Screening Unit of Clinical Genetic Service started its territory-wide neonatal screening program for G6PD deficiency and congenital hypothyroidism in 1984 (Lam et al, 1986). Because of insufficient manpower and resource, we have been giving health counseling on the phone to parents of G6PD deficient babies and then refer them to nearby maternal and child health centres for monitoring of jaundice. The disease, mode of inheritance, recurrence risk and the precaution against certain medicines (Chan 1996) and chemicals are explained. The purpose (Lam, 1994) is to reassure the parents that their G6PD deficient babies can be as normal as everyone and that they can have normal life. Nevertheless, it has not been established whether telephone counseling has any effect on the affected family in the form of psychological trauma (Marteau, 1989; Fyro, 1987; Li et al, 1996) or significant influence on the decision on future reproduction. This study tried to evaluate the service from the parents' point of view by 1) gathering information on parents' awareness and perception of G6PD deficiency, 2) determination of parents' attitude towards the telephone counseling, and 3) finding out the effect of G6PD deficiency on parents' decision on future reproduction. Over 300 parents were contacted by telephone, and were asked to respond to questions on a questionnaire . The telephone interview focused on parents' understanding of G6PD deficiency, their attitude towards this disease and the possible effect on future reproduction decision. Results showed that over 90% of cases that we had counseled attended the maternal and child health centres. Most of them accepted the presence of G6PD deficiency in their family which did not affect their decision on future pregnancy. Telephone counseling failed to establish a helping relationship with the parent as face to face counseling was more personal. The findings revealed that though telephone counseling had its shortcoming it served the target group effectively. Telephone counseling is still the method of choice for the G6PD deficiency counseling in this locality.

[The prevention of hereditary erythrocytic diseases]. / Profilaxia das doenças hereditárias do eritrócito.

The authors report the importance of not only all over the world but also in Portugal and, particularly, in Dona Estefânia Hospital. Some considerations are made about the usefulness of molecular biology methods in prenatal diagnosis. With this tool can also be do the origins and migrations of populations, which contributes to the knowledge of aspects of our history. Finally, they present consensual attitudes which should adopt regarding these chronic diseases, with special emphasis to the prophylactic aspects.

Hereditary anaemias in Portugal: epidemiology, public health significance, and control.

A countrywide prospective study aimed at establishing the prevalence of the haemoglobinopathy genes in the Portuguese population was carried out by screening 15,208 randomly selected blood samples from young males. This male based survey provided the opportunity of assessing simultaneously the prevalence of the red cell enzyme glucose-6-phosphate dehydrogenase (G6PD) deficiency, thus giving a picture of these important hereditary anaemias in Portugal. The results showed a low average frequency of beta thalassaemia (0.45%) and haemoglobin S (0.32%) carriers as well as G6PD deficiency (0.51%). However, these disorders are unevenly distributed throughout the country with a higher prevalence in some areas, mainly in the south. The relationship of this pattern of haemoglobinopathies to the known haplotypes linked to beta thalassaemia and sickle cell disease, relevant historical events, and local selective pressure was investigated. Hb D and Hb J are the commonest other structural variants. The implemented programme for control of these hereditary anaemias is described.

Marked decline of favism after neonatal glucose-6-phosphate dehydrogenase screening and health education: the northern Sardinian experience.

Favism is a potentially fatal manifestation of glucose-6-phosphate dehydrogenase (G6PD) deficiency, and it is therefore a public health problem in areas where this genetic abnormality is common. In the district of Sassari (northern Sardinia), the frequency of G6PD male hemizygotes is approximately 7.5%, and therefore all newborns since 1971 have been screened for G6PD deficiency. We have analyzed the incidence of favism in this community in two 10-year periods: (1) 1961-1970; and (2) 1981-1990. In period 1, there were 508 cases of favism, of which 76% occurred in boys. In period (2) there were 144 cases of favism, of which only 52% in boys. Thus, between the two periods there was an overall decrease in the incidence of favism of 75%, whereas the proportion of girls affected has approximately doubled. These data suggest that neonatal screening and health education programs can produce a substantial decrease in the number of cases of favism, and that the relative increase in favism in girls is possibly due to failure of the screening method used to detect all the heterozygotes for G6PD deficiency.

Screening for glucose-6-phosphate dehydrogenase deficiency as a preventive measure: prevalence among 1,286,000 Greek newborn infants.

We evaluated the Greek screening program for glucose-6-phosphate dehydrogenase (G6PD) deficiency, which was incorporated into the existing national phenyketonuria (PKU) screening program to identify infants with G6PD deficiency and eliminate the induction of acute hemolytic crisis by informing the families about the extrinsic factors that G6PD-deficient patients should avoid. Between 1977 and 1989, 1,286,000 infants were screened. The fluorescent spot test was used on samples extracted from dried blood spots. Abnormal fluorescence due to G6PD deficiency (severe or partial) was found in 3.14% of the samples (1 in 22 males and 1 in 54 females). The sensitivity of the test for homozygosity and hemizygosity was 100%. In heterozygosity the test identifies only subjects who have considerably diminished enzyme activity. The test is inexpensive when added to the PKU screening program ($0.90 US per test). We believe that screening a population for G6PD deficiency is justified if the incidence of the deficiency in the population is high and the clinical manifestations serious. The fluorescent spot test is recommended because it is reliable, easy to perform, and inexpensive. The test must be performed within a fortnight from sampling, and the cards must not be exposed to high temperature or humidity.