OBJECTIVETo summarize the molecular epidemiology of hemoglobinopathies in Yongzhou area of Hunan province in order to provide a basis for making the guidelines of local thalassemia prevention program.

METHODSTwo thousand and two samples (1001 couples) were randomly recruited based on demographic data and distribution of ethnic groups. All samples were subjected to full blood count and analysis of hemoglobin and 6 common alpha-thalassemia mutations. Known beta-thalassemia mutations were screened in samples with beta-thalassemia trait. The remaining samples with positive phenotype and unknown mutations were subjected to DNA sequence analysis.

RESULTSTwo hundred and forty individuals were found to be carriers of hemoglobinopathic mutations, which included 6 common alpha-thalassemia deletions, 9 common beta-thalassemia mutations and 3 common structural hemoglobin variants. One hundred and seventy-four mutant alleles for alpha-thalassemia were detected, which gave a carrier rate of 8.69%, of which 0.1% was due to HbH disease. Seventy mutant alleles for beta-thalassemia were detected, which gave a carrier rate of 3.50%. Seven subjects (0.35%) were identified as carriers of hemoglobin variants. The overall carrier rate for hemoglobinopathic mutations was 12.54% based on detection of 251 hemoglobinopathy mutant alleles. The overall carrier rate for alpha- and beta-thalassemia among ethnic Yaos was 25.00%, which was significantly higher than that of ethnic Han Chinese (11.14%, P< 0.01).

CONCLUSIONThe prevalence and mutation spectrum of hemoglobinopathies in Yongzhou area has been delineated for the first time.