[Genotype of Thalassemia in Han Chinese and Tibetans in Sichuan Province,China.]

OBJECTIVES: To investigate the carrying rates and genotype distribution of thalassemia gene in Han people and Tibetans in Sichuan district.

METHODS: A total of 1 147 Han adults and 613 adult Tibetans were included in this study.Hematological parameters were measured with Sysmex XE-2100 automatic blood cell analyzer.Alpha thalassemia and beta thalassemia gene analyses were further performed on samples with a mean corpuscular volume (MCV) <85 fL and a mean corpuscular hemoglobin (MCH) <27 pg.Multiplex ligation-dependent probe amplification (MLPA) and reverse dot blot assays were used for detecting deletional mutations of α globin gene and non-deletional mutations of α globin and β globin genes,respectively.

RESULTS: About 1.48% (17/1 147) Han people carried alpha thalassemia gene,with --SEA /αα as the most common genotype; 1.39% (16/1 147) carried beta thalassemia gene,with CD17 and IVS-2-654 as the most common genotype.There were 2 cases with both alpha and beta thalassemia.Low MCH (<27 pg) was found in all 33 cases with positive thalassemia genes.However,5 people with positive thalassemia genes had higher than 80 fL MCV,with the highest reaching 83.7 fL.Out of 613 Tibetans,only one was found to have positive thalassemia genes.

CONCLUSIONS: Sichuan Han population carry a high level of thalassemia genes,with various genotypes and pathogenic gene mutation types.Han people with < 84 fL MCV and <27 pg MCH were recommended for thalassemia gene screening.Tibetans were not recommended for routine screening of thalassemia.