[Gene Detection Analysis of Thalassemia in 2 494 Cases of Childbearing Couples in Haikou City]

Abstract

Objective: To observe the genotypes and composition ratio of thalassemia in couples of reproductive age, and provide a reference for the prevention and control of thalassemia in Haikou.

Methods: Gene diagnosis was performed in 2 494 subjects who were screened for thalassemia before marriage or prenatal by cross-breakpoint PCR, PCR-reverse dot hybridization, and PCR-electrophoresis.

Results: A total of 1 037 thalassemia gene carriers were detected in 2 494 samples, with a detection rate of 41.57%, of which 75.02% was α-thalassemia, 18.61% was β-thalassemia, and 6.36% was α-β complex thalassemia. There were 778 cases of α-thalassemia, mainly of deletion type, accounting for 76.99% (599/778). Twenty genotypes were detected, the highest three was --^SEA/αα (33.42%, 260/778), -α^3.7/αα(23.91%, 186/778), and -α^4.2/αα(19.02%, 148/778), respectively. A rare HKαα/-α^3.7 was detected, who immigrated from other province. There were 193 cases of β-thalassemia, all of them were light (β⁰/β^A or β⁺/β^A). Eight genotypes were detected, the highest two was 41-42M/N (74.61%, 144/193) and 654M/N (10.36%, 20/193), respectively. There were 66 cases of α-β compound type of thalassemia, 15 genotypes were detected, the highest three was αα^WS/αα complex 41-42M/N (28.79%, 19/66), -α^3.7/αα complex 41-42M/N, and -α^4.2/αα complex 41-42M/N (16.67%, 11/66 for both).

Conclusion: In Haikou city, the gene carrying rate of thalassemia is very high, and the genotype distribution is different from other cities in Hainan Province, attention should be paid to the impact of population inflow on the frequency spectrum change of local thalassemia gene.