An analysis of genetic screening results of thalassemia among couples of reproductive age in Dongfang City of Hainan Province

Objective To investigate the genetic carrier rate of thalassemia and its gene mutation types as well as the distribution characteristics among couples of reproductive age in Dongfang City of Hainan Province, and to provide a basis for making prevention and control strategies against thalassemia. Methods Samples were collected from 1 000 couples undergoing premarital and pregestational screenings for thalassemia in Dongfang City of Hainan Province from September 2012 to March 2013, in which the positive ones in preliminary screening were further tested by genetic diagnoses and the genotypes were retrospectively analyzed. Results Among 1 000 couples, 322 spouses were diagnosed with thalassemia gene mutation and the carrying rate was 16.10% (322/2 000). In those carriers, 246 spouses were α-thalassemia and the carrying rate was 12.30% (246/2 000), accounting for 76.40% (246/322) of all thalassemia carriers, among them, there were 197 cases of α-deficiency genotype, accounting for 61.18% (197/322), 32 carried mutated α-gene, accounting for 9.94% (32/322), 17 carried both deleted and mutated α-gene, accounting for 5.28% (17/322); 43 spouse were β-thalassemia and the carrying rate was 2.15% (43/2 000); 33 spouse were both α- and β-thalassemia and the carrying rate was 1.65% (33/2 000). In spouses diagnosed with α-thalassemia, the major genotype was-α3.7/αα, accounting for 19.25% (62/322); the second ranked was-α4.2/αα,accounting for 17.70% (57/322), and the third ranked was--SEA/αα, accounting for 8.70% (28/322). In spouses diagnosed with β-thalassemia, the major genotype was CD41-42/N, accounting for 9.63% (31/322). Conclusions The population carrying rate of thalassemia in Dongfang City of Hainan Province is high, and its major type is α-thalassemia. For the purpose of decreasing the birth rate of thalassemia, major, local public health department should attach great importance to thalassemia prevention, and strengthen premarital and pregestational screening for thalassemia. Key words: Thalassemia; Couples of reproductive age; Genotype