An interesting case of anemia with jaundice

Hemoglobinopathies are haematalogical disorders that afflict millions of individuals worldwide. HbE is a hemoglobinvariation caused by a mutation in the ? globin gene that results in the substitution of glutamic acid for lysine at position 26 of the ? globin gene. Hemoglobin (Hb) synthesis abnormalities are among the most prevalent inherited disorders. They can be quantitative (thalassemia syndrome) or qualitative (variant HbS). Hemoglobin E (HbE) is the second most common hemoglobin variation after hemoglobin S (HbS).

Hematological and genotypic features of 100 patients with hemoglobin E disorders from Yunnan Province / 中华医学遗传学杂志

Objective@#To explore hematological and genotypic characteristics of patients with hemoglobin E (Hb E) disorders from Yunnan Province.@*Methods@#One hundred individuals with Hb E disorders indicated by high performance liquid chromatography (HPLC) were subjected to genetic testing through multiple gap-PCR and reverse dot-blotting analysis.@*Results@#All patients were found to harbor a mutation to the 26th codon of the β-globin chain (HBB: c. 79G>A). Ninety patients were heterozygotes, and 10 co-inherited c. 79G>A and an α-thalassemia mutation (7 αα/-α3.7, 2 αα/--SEA and 1 -α3.7/-α3.7). Hematological characteristics of the heterozygotes were: Hb A2 (26.02±3.64)%, Hb F(1.35±1.25)%, MCV(78.83±4.68) fl, MCH(26±1.54) pg, MCHC (329.65±10.73) g/L, HGB (141.08±16.53) g/L, while that of the co-inherited cases was decided by the type of α-thalassemia mutation.@*Conclusion@#Hb E can be effectively detected by HPLC. The type of α-thalassemia mutations will determine hematological features of co-inherited cases. Hb E disorders may be missed by relying only on routine blood test upon prenatal screening.

Hemoglobin A1c Levels Are Slightly but Significantly Lower in Normoglycemic Subjects With the Hemoglobin E Phenotype

Hb mutations can alter the structure, behavior, stability, or quantity of the globin chain produced. Some Hb variants shorten the erythrocyte life span, resulting in physiologically lower hemoglobin A1c (HbA1c) levels. The hemoglobin E (HbE) phenotype involves a single-nucleotide polymorphism that reduces β-globin chain synthesis. We compared the HbA1c levels of subjects with normal Hb (HbAA; N=131) and HbE (N=148) phenotypes, examining potential hematological and biochemical factors contributing to differences in HbA1c levels. All had normal fasting plasma glucose ( < 5.6 mmol/L), AST, ALT, and creatinine levels. Mean±SD HbA1c levels differed between HbAA and HbE subjects: 5.5±0.3% and 5.3±0.3% (P < 0.001) according to an immunoassay, and 5.5±0.3% and 5.3±0.3% (P < 0.001) according to cation-exchange HPLC, respectively. In multiple logistic regression, only mean corpuscular volume (P < 0.001) contributed to the difference in HbA1c levels between groups. Although a 0.2% difference in HbA1c is relatively small and unlikely to alter clinical decisions, epidemiologically, this can lead to misclassification of a significant proportion of the population, especially since the threshold of non-diabetes HbA1c (≤5.6%) falls very close to the HbA1c median of the general population.

Endogamous marriage and the prevalence of hemoglobin E in ethnic groups of northern Thailand

OBJECTIVE@#To investigate the impact of the endogamous marriage culture on the prevalence of the hemoglobin E (HbE) recessive variant.@*METHODS@#The prevalence of the hemoglobin E (HbE) recessive variant was determined by dot-blot hybridization in 4 endogamous villages (1 Mlabri and 3 Htin ethnic groups) in comparison with 9 other nearby non-endogamous populations.@*RESULTS@#Although the overall HbE prevalence in the population studied (8.44%, 33/391) was not significantly different from that of the general southeast Asian population, a high prevalence and individuals with homozygous HbE were observed in two villages, the Mlabri from Wiang Sa district and the Htin from Thung Chang district of Nan province (26.3% and 26.9%, respectively). The low HbE allelic frequency noticed in some endogamous populations suggests that not only endogamy but also other evolutionary forces, such as founder effect and HbE/β-thalassemia negative selection may have an effect on the distribution of the HbE trait.@*CONCLUSION@#Our study strongly documents that cultural impact has to be considered in the extensive prevalence studies for genetic disorders in the ethnic groups of northern Thailand.

Endogamous marriage and the prevalence of hemoglobin E in ethnic groups of northern Thailand

Objective To investigate the impact of the endogamous marriage culture on the prevalence of the hemoglobin E (HbE) recessive variant. Methods The prevalence of the hemoglobin E (HbE) recessive variant was determined by dot-blot hybridization in 4 endogamous villages (1 Mlabri and 3 Htin ethnic groups) in comparison with 9 other nearby non-endogamous populations. Results Although the overall HbE prevalence in the population studied (8.44%, 33/391) was not significantly different from that of the general southeast Asian population, a high prevalence and individuals with homozygous HbE were observed in two villages, the Mlabri from Wiang Sa district and the Htin from Thung Chang district of Nan province (26.3% and 26.9%, respectively). The low HbE allelic frequency noticed in some endogamous populations suggests that not only endogamy but also other evolutionary forces, such as founder effect and HbE/β-thalassemia negative selection may have an effect on the distribution of the HbE trait. Conclusion Our study strongly documents that cultural impact has to be considered in the extensive prevalence studies for genetic disorders in the ethnic groups of northern Thailand.

Coexistence of Malaria and Thalassemia in Malaria Endemic Areas of Thailand

Hemoglobinopathy and malaria are commonly found worldwide particularly in malaria endemic areas. Thalassemia, the alteration of globin chain synthesis, has been reported to confer resistance against malaria. The prevalence of thalassemia was investigated in 101 malaria patients with Plasmodium falciparum and Plasmodium vivax along the Thai-Myanmar border to examine protective effect of thalassemia against severe malaria. Hemoglobin typing was performed using low pressure liquid chromatography (LPLC) and alpha-thalassemia was confirmed by multiplex PCR. Five types of thalassemia were observed in malaria patients. The 2 major types of thalassemia were Hb E (18.8%) and alpha-thalassemia-2 (11.9%). There was no association between thalassemia hemoglobinopathy and malaria parasitemia, an indicator of malaria disease severity. Thalassemia had no significant association with P. vivax infection, but the parasitemia in patients with coexistence of P. vivax and thalassemia was about 2-3 times lower than those with coexistence of P. falciparum and thalassemia and malaria without thalassemia. Furthermore, the parasitemia of P. vivax in patients with coexistence of Hb E showed lower value than coexistence with other types of thalassemia and malaria without coexistence. Parasitemia, hemoglobin, and hematocrit values in patients with coexistence of thalassemia other than Hb E were significantly lower than those without coexistence of thalassemia. Furthermore, parasitemia with coexistence of Hb E were 2 times lower than those with coexistence of thalassemia other than Hb E. In conclusion, the results may, at least in part, support the protective effect of thalassemia on the development of hyperparasitemia and severe anemia in malaria patients.

Hemoglobin E disorder: Newborn screening program.

Hemoglobin E (Hb E) disorder is an important kind of hemoglobinopathy. It can be seen around the world with the highest prevalence in Southeast Asia. The screening for this disorder becomes the public health policies in many countries. The screening can be performed in several population groups. The newborn screening program for Hb E disorder is an important issue in pediatric genetics. In this brief review, the author discusses on important laboratory tests for screening for Hb E disorder in newborn.

Method for detection of gene mutation of hemoglobin E in population of Sichuan area / 临床检验杂志

Objective To establish a PCR-RFLP method for detection of CD26 mutation of hemoglobin E(HbE)gene.Methods The genome DNA from the family members who were suspected of having HbE combined with beta-thalassemia was amplified using PCR.The PCR products were digested by restriction endonuclease Mnl I,and then separated on PAGE.The electrophoretical patterns were finally analyzed to confirm if CD26 mutation was present or not.Results Four cases with CD26 mutation in two families were successfully screened out.Conclusion Although the incident frequency of CD26 mutation in Sichuan population is not high,it must not be neglected since it may present alone or combined with other type of thalassemia.PCR-RFLP method described in this study is available in screening mutated HbE gene and treating the disease owing to its simplicity,rapidity and specificity.