Evaluation of intervention strategy of thalassemia for couples of childbearing ages in Centre of Southern China

Background: To describe the free intervention strategy of thalassemia for childbearing couples in Guangzhou.

Methods: Routine hematology examinations were conducted for 137,222 couples. Among them, 37,501 couples who had mean corpuscular volume (MCV) <82 fL or mean corpuscular hemoglobin <27 pg were elected for Hb analysis and the deletions of four common α-thalassemia mutation. Reverse dot blot for common nondeletional α-thalassemia and β-thalassemia was selectively used. Three thousand twenty-two couples randomly selected were offered all those tests as a control group. Sanger sequencing, multiplex ligation-dependent probe amplification and next-generation sequencing were used for rare thalassemia. High-risk couples were offered prenatal diagnosis at 10-13 weeks' gestation based on informed consent.

Results: The carrier rates of α-, β-, and αβ-thalassemia and δβ thalassemia/deletional HPFH were 7.7%, 3.02%, 0.5% and 0.059% respectively. Of them, 1.37% were identified as at-risk couples and 345 couples terminated the pregnancy. No severe α- and β-thalassemia births were observed. In the control group, two β- thalassemia carriers and one case with -α^3.7 /αα^QS were misdiagnosed, but all at-risk couples were found, and we could save 1,523,774 ¥ using our strategy. The cut-off points of 73.46 fL and 23.25 pg would be useful to find -α⁺ /α^T thalassemia.

Conclusion: The intervention strategy was cost-effective and offered reference in population thalassemia screening.