Chronic nonspherocytic hemolytic anemia due to glucose-6-phosphate dehydrogenase deficiency: report of two families with novel mutations causing G6PD Bangkok and G6PD Bangkok Noi.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the most common hereditary enzymopathies worldwide. Mostly G6PD deficient cases are asymptomatic though they may have the risk of neonatal jaundice (NNJ) and acute intravascular hemolysis during oxidative stress. Chronic nonspherocytic hemolytic anemia (CNSHA) due to G6PD deficiency is rare.

Development of a comprehensive red blood cell enzymopathy laboratory in Thailand: the study of normal activity in eight erythroenzymes in Thais.

In order to provide a reference range for normal red blood cell enzyme activities in Thai, we analyzed data from 113 healthy non-anemic Thai people (55 males and 58 females) age 1-42 years, who all had a normal pattern of hemoglobin typing (HbA and HbA2 less than 3.5%). Hematological analysis was performed using an automated cell counter and the hemoglobin studies were carried out by low pressure liquid chromatography.

Clinical and hematological phenotype of homozygous hemoglobin E: revisit of a benign condition with hidden reproductive risk.

Hemoglobin E (HbE) is one of the most prevalent beta-globin variant, which is widely distributed in Southeast Asia especially in Thailand. Homozygosity for this variant is common and may occur with iron deficiency. In order to study clinical and hematological phenotypes without the confounding effect of iron deficiency, investigations were carried out before and after iron supplementation for 2 months.

Molecular analysis of unknown beta-globin gene mutations using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique and its application in Thai families with beta-thalassemias and beta-globin variants.

Objectives: Approximately 40 beta-globin gene mutations have been identified in Thailand. The detection of these mutations is currently performed by the reverse dot blot (RDB) hybridization technique, which could detect only known mutations. We describe here the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) assay for detecting unknown mutations of the beta-globin genes.

Identification of Hb Q-India (alpha64 Asp-->His) in Thailand.

More than 30 different hemoglobin variants either affecting alpha or beta globin chains have been identified in Thailand. The large variety in the different forms of hemoglobinopathy contributes to several complicated interactions, since different types of defective globin alleles are prevalent in Thailand and nearly 30-40% of the population are carriers of either alpha or beta thalassemia (thal). Many rare and novel abnormal globin variants in Thai subjects have been identified in our laboratory within the past few years; including Hb Lepore-Hollandia, homozygous Hb Tak, Hb Dhonburi, Hb G-Makassar, Hb G-Coushatta, Hb New York, Hb Paksè and Hb Pak Num Po.

Prevalence of HFE mutations among the Thai population and correlation with iron loading in haemoglobin E disorder.

Co-inheritance of HFE mutations has a substantial role in iron overload in beta-thalassaemia carriers in north European populations where two HFE mutations, C282Y and H63D, are prevalent. In Thailand, there was little information about the allele frequency of HFE mutations. It is of interest to determine whether such determinants represent a potential risk in developing iron overload as nearly 40% of the Thai population carry either one of thalassaemia or haemoglobinpathy alleles.

Co-inheritance of Hb Pak Num Po, a novel alpha1 gene mutation, and alpha0 thalassemia associated with transfusion-dependent Hb H disease.

Hb H disease is generally associated with moderate to severe anemia but rarely requires regular blood transfusion. We recently studied two apparently unrelated patients with transfusion-dependent Hb H disease. Hemoglobin studies demonstrated Hb H and Hb Bart's without other detectable abnormal globin species.

The validation of an automated liquid chromatography system for the diagnosis of thalassemias and hemoglobinopathies.

Accurate and precise hemoglobin separation and the quantitation of Hb A2 and Hb F are essential for the diagnosis of the thalassemias and hemoglobinopathies. Presented in this study is the validation of the the Hb A2 assay of the HbGold analyzer, a fully automated liquid chromatography system for hemoglobin separation and quantitation. Variability of Hb A2 quantitation was quite low; the CV's of within-run, between-run and interlaboratory studies were 1.

Allele related mutation specific-polymerase chain reaction for rapid diagnosis of Hb New York (beta 113 (G15) Val-->Glu, beta(CD113 GTG-->GAG)).

Hemoglobin New York (beta 113 (G15) Val-->Glu), a beta-globin variant, was first reported in a Chinese family living in New York. Subsequently, this abnormal hemoglobin was reported in many Chinese descendants from several groups and it was also known as Hb Kaohsiung. The subtle change in alpha1beta1 contact region apart from the heme group connecting area by Val-->Glu substitution has minor changes in both the electrophoretic mobility and stability making this hemoglobin variant difficult to distinguish from Hb A using routine hemoglobin analysis.

Effect of red blood cell glucose-6-phosphate dehydrogenase deficiency on patients with dengue hemorrhagic fever.

Eighty nine males aged 1-13 years diagnosed with dengue haemorrhagic fever (DHF) and admitted to the Department of Pediatrics Siriraj Hospital from March 1998 to April 2000 were included in this study. 17 cases (19.1%) had red blood cell glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and 72 cases (80.

Carrier detection by DNA linkage analysis in eighty Thai hemophilia A families.

DNA linkage analysis was performed in Thai hemophilia A families to evaluate its value for carrier detection. Both intragenic and extragenic polymorphic DNA regions of the factor VIII gene, including Bcl I-RFLP in intron 18, microsatellites (CA repeats) in introns 13 and 22, and extragenic Stl4 (DXS 52) VNTR, were amplified by polymerase chain reaction (PCR) before analyses by appropriate electrophoretic procedures. A total of 80 Thai hemophilia A families (48 with a family history and 32 with a sporadic case), containing 349 DNA samples from 90 hemophilia A patients, 143 parents, and 116 relatives, were analyzed.

Complex interactions of deltabeta hybrid haemoglobin (Hb Lepore-Hollandia) Hb E (beta(26G-->A)) and alpha+ thalassaemia in a Thai family.

Haemoglobin Lepore-Hollandia is an extremely rare condition in which a small deletion gives rise to a deltabeta hybrid, beta-like globin. There are two single reports of patients from South Pacific Islands and Bangladesh. We describe a family from central Thailand, in which this Hb Lepore-Hollandia interacts with a common beta globin variant (beta(E) resulting from the codon 26, G-->A mutation) and alpha(+) thalassaemia (alpha(3.

Clinical phenotypes and molecular characterization of Hb H-Paksé disease.

Background And Objectives: Hemoglobin Constant Spring (Hb CS), caused by a termination codon mutation (TAA-->CAA) in the a2 gene, is the most common non-deletional type of a thalassemia in Southeast Asia. This mutation can most easily be detected by loss of an MseI-restriction site (T/TAA) spanning the termination codon. Recently, we sequenced the a globin genes from patients with a thalassemia in whom this MseI site was absent.