Abstract:

Objective To analyze the results of prenatal gene determination retrospectively in 91 couples with same type thalassemia,and to provide effective genetic counseling. Methods From January 2016 to December 2017,pregnant women and their husbands receiving routine prenatal examination or genetic counseling for eugenics in Nanning Second People's Hospital were enrolled. Totally,74 couples with α-thalassemia,13 couples with β-thalassemia and 4 couples with α- and β-double thalassemia were confirmed. Genomic DNA was extracted from amniotic fluid. Gap polymerase chain reaction （Gap-PCR） and polymerase chain reaction-reverse blot hybridization assay （PCR-RDB） were used to determine the missing and mutation of thalassemia,meanwhile the karyotype was analyzed. Results In 74 couples of α-thalassemia,the main gene types were --^SEA/αα（36.5%）,--^SEA/-- ^SEA（14.9%）,-α^3.7/αα（9.5%） and α^WS α/αα（6.8%）. In 13 couples of β-thalassemia,heterozygous mutation accounted for 61.5%,double heterozygous mutation accounted for 23.1%,and homozygous mutation accounted for 7.7%。There were 4 couples of α- and β-double thalassemia,and α- and β-double thalassemia was also found in their fetuses. There were 15 fetuses of severe thalassemia,and they were all aborted. Conclusions Thalassemia screening before pregnancy and prenatal thalassemia gene determination are effective means on reducing the birth of severe thalassemia in high-risk thalassemia region.

Key words: Gene determination, Karyotype analysis, Thalassemia