Genetic analysis of couples with positive results in thalassemia screening in Baise

Objective To provide reference for thalassaemia genetic counseling by revealing the genetic diagnosis of couples whose thalassaemia screening were both positive in Baise district.Methods 450couples with positive results in thalassaemia screening,who were transferred to a prenatal diagnositic center for thalassemia from January,2010to December,2011,were given genetic analysis.The proportion and prenatal diagnostic results of high risk couples with thalassemia were calculated.Results Among 900detected chromosomes,243allelicmutants were found inα thalassemia with a frequency of 27.0% and 144allelicmutants were found inβthalassemia with a frequency of 16.0%.The genetic testing results showed that within the 450couples,20% of couples were carriers or patients of different types of thalassemia and 43% of couples were carriers or patients of the same type of thalassemia,of which high risk couples with thalassemia covered 85.6%.26%of all the couples had only one partner as carriers of thalassemia.11%of all the couples were proved healthy in the genetic detection.80.1%of pregnant women went for prenatal diagnosis.27.8% of them had healthy fetus and 30.1% had fetus with thalassemia major or thalassemia intermedia(α-thalassemia,β-thalassemia orα-combined withβ-thalassemia).33fetus with thalassemia major or thalassemia intermedia were avoided.Conclusion High risk couples with thalassemia accounted for a considerable proportion in couples who got positive results in thalassemia screening in Baise district.Thus,to have large scale of population screening,genetic diagnosis experiment,genetic counseling and prenatal diagnosis for high risk thalassemia fetus are the best ways to avoid fetus with thalassemia major to come to birth.