[Thalassemia Gene Detection Results and Application Value of Hematological Indexes Among Pregnant Women in Xindu District of Chengdu City].

Objective: To analyze the genotype characteristics of α- and β-thalassemia and the diagnostic value of hematological indexes in pregnant women in Xindu District of Chengdu.
Methods: The blood routine parameters(MCV) <80 fl and (or) (MCH) <27 pg and hemoglobin electrophoresis were used to screen the pregnant women, PCR-reverse dot blot hybridization(PCR-RDB) technique was used to detect the common α- and β-thalassemia gene types in the primary screening positive population. The husbands of the diagnosed pregnant women were recalled for gene testing, and the highly suspected patients were checked by gene sequencing.
Results: Among the 7 049 pregnant women, 1 740(24.68%) cases were positive for primary screening. 180 patients were diagnosed as thalassemia gene positive, among them, 94 cases (52.22%) of α-thalassemia were detected and six genotypes were found, in which -- ^SEA /αα genotype was the highest (58 cases, 61.70%); 82 cases (45.56%) of β-thalassemia were detected and ten genotypes were found while CD41-42/N and CD17/N genotypes were the most common; there were 4 cases(2.22%) with α combined with β-thalassemia. Through clinical follow-up survey, there were 4 couples with the same type of thalassemia, one of them was induced labor after diagnosis of hemoglobin H disease. Receiver operating curve (ROC curve) was used to analyze the diagnostic value of hematological parameters in thalassemia positive pregnant women. The results showed that AUC(HBA ₂ )<AUC(MCHC)<AUC(RDW-SD)<AUC(MCH)<AUC(MCV) (P<0.01).
Conclusion: The most common genotypes of α- and β-thalassemia in pregnant women in Xindu District of Chengdu were -- ^SEA /αα, CD41-42/N, CD17/N. The blood routine indicators (HBA ₂ 、RDW-SD、MCHC、MCH、MCV) have high diagnostic value for screening of thalassemia.