Hemoglobin Constant Spring is markedly high in women of an ethnic minority group in Vietnam: a community-based survey and hematologic features.

A community-based survey was conducted to determine the prevalence and gene frequency of Hemoglobin Constant Spring (Hb CS) and other forms of thalassemia among an ethnic minority in Vietnam. A total of 298 ethnic minority women, the Có-Tu, participated. Hematological parameters and hemoglobin profiles were analyzed using standard automated analyzers. Alpha- and beta-thalassemia mutations were identified using polymerase chain reaction (PCR) based technology. Of the 298 women, 141 (47.3%) carried thalassemia genes. Hemoglobin Constant Spring (Hb CS) is the most common with a markedly high frequency of 0.143 (overall prevalence=26.2%). The heterozygous state of Hb CS was found in one-fifth (20.5%) of women participating. Seven women (2.4%) were Hb CS homozygote. The overall prevalence for Hb E was 13.8%, and 10.7% for α(+)-thalassemia. Other forms of thalassemia included 0.67% β-thalassemia, and 0.34% Hb Paksé. None of the participants had the α(0)-thalassemia gene. The study provides basic epidemiological information about Hb CS as well as other forms of thalassemia for a specific group of an ethnic minority in Vietnam. The data will be useful for further study on the distribution of thalassemia in Southeast Asia.