In this paper, we reported a 23‐year‐old pregnant woman who showed a typical α0‐thalassemia (‐‐SEA deletion) trait (Hb 90 g/L, MCV 71 fL, MCH 22.7 pg) and a β+‐thalassemia -90 (C>T) (HBB: c.‐140 C>T) phenotype (MCV 71 fL, MCH 22.7 pg and HbA2 5.51%) and her fetus was identified to have rare compound heterozygotic mutations of the ‐‐SEA/‐α4.2 deletions combined with β+‐thalassemia gene -90 (C>T) (HBB: c.‐140 C>T) mutation (Myers et al., 1986), which was inherited from the pregnant mother and the α‐thalassemia carrier father α+‐thalassemia mutation [‐α4.2 (leftward)]. The gene discussed is GSTM1; the disease is thalassemia.