Clinical Value of PCR-flow Fluorescence Hybridization in Prenatal Genetic Diagnosis of Thalassemia

OBJECTIVE:To explore the value of PCR-flow fluorenscence immunmicrobeads assay in prenatal gene diagnosis of thalassemia.METHODS:A total of 1001 pregnant women and their couples checked in the First Affiliated Hospital of Sun Yat-Sen University from January 2016 to August 2019 were selected. Both pregnant women and their spouses were the carriers of thalassemia gene. Samples such as amniotic fluid, were used to extract genomic DNA at the right time. Parallel detection of α- and β- thalassemia genes to samples should be carried out by PCR-flow cytometric fluorescence hybridization and traditional multiple Gap-PCR and PCR-RDB techniques. The consistency of two methods in gene diagnosis of thalassemia was evaluated by analyzing the results of detection.RESULTS:389 normal genotypes (38.86%, 389/1001) and 59 abnormal genotypes (61.14%, 612/1001) was cheked out by the two methods, including 416 cases of α-thalassemia, 162 cases of β-thalassemia and 34 cases of αβ- complex thalassemia. The main genotypes of α-thalassemia were --SEA, -α3.7 and -α4.2. The mutation frequency of CD41-42 was the highest among the β-thalassemia genotypes, which followed by IVS-II-654 and CD17. A rare HKαα/--SEA thalassemia genotype was detected. Compared the traditional multiple Gap-PCR and PCR-RDB techniques, the sensitivity, specificity, positive predictive value, negative predictive value and total consistent rate of PCR-flow fluorenscence immunmicrobeads assay were 100%, which showed that the two methods were completely consistent.CONCLUSION:Guangzhou is a area with high incidence of thalassemia, and the genetic types of thalassemia are complex and diverse. Prenatal diagnosis is the final barrier to the prevention of thalassemia. PCR flow-cytometric fluorescence hybridization, as a simple and fast technique, combined with traditional techniques in parallel contributed to the accuracy of prenatal gene diagnosis of thalassemia.