Hemoglobin Yusa (beta 21 (B3) Asp leads to Tyr), a new abnormal hemoglobin found in Japan

Next-generation sequencing improves molecular epidemiological characterization of thalassemia in Chenzhou Region, P.R. China

Objectives

Thalassemia is a highly prevalent monogenic inherited disease in southern China. It is important to collect epidemiological data comprehensively for proper prevention and treatment.

Methods

In this study, blood samples collected from 15 807 residents of Chenzhou were primarily screened by hematological tests. A total of 3973 samples of suspected thalassemia carriers were further characterized by combined next‐generation sequencing (NGS) and Gap‐PCR.

Results

In total, 1704 subjects were diagnosed as thalassemia carriers with a total prevalence rate of 10.78%, including 943 α‐thalassemia carriers, 708 β‐thalassemia carriers, and 53 composite α and β‐thalassemia carriers. The prevalence rates of α‐thalassemia, β‐thalassemia, and composite α and β‐thalassemia were 5.97%, 4.48%, and 0.34%, respectively. Meanwhile, we characterized 19 α‐thalassemia variations and 21 β‐thalassemia variations in thalassemia carriers. Approximately 2.88% of thalassemia carriers would be missed by traditional genetic analysis. In addition, four novel thalassemia mutations and one novel abnormal hemoglobin mutation were identified.

Conclusions

Our data suggest a high prevalence of thalassemia and a diverse spectrum of thalassemia‐associated variations in Chenzhou. Also, combined NGS and Gap‐PCR is an effective thalassemia screening method. Our findings might be helpful for prevention and treatment of thalassemia in this region.

Hb Karlskoga or alpha 2 beta (2)21(B3) Asp-->His: a new slow-moving variant found in Sweden

An abnormal variant comprising approximately 39% of total hemoglobin was found in a 48-year-old Swedish woman. The variant was eluted from ion exchange high performance liquid chromatography (HPLC) used for routine quantification of Hb A1c at a position similar to Hb S. Amplification of beta-globin exons and nucleotide sequencing revealed heterozygosity for a GAT-->CAT mutation in codon 21, corresponding to the amino acid substitution Asp-->His at position 21. This mutation was confirmed by amino acid composition and peptide sequence determinations. Substitutions in this position are not likely to affect the function of the hemoglobin molecule and the hemoglobin variant, for which the name Hb Karlskoga is proposed, was not associated with any overt hematological abnormalities.