HbA2 :c.96-2A > G mutation: report of 7 cases in China.

Objective: To analyze the hematological phenotype and genotype of HbA2 : c.96-2A > G carriers.
Methods: The blood routine parameters and hemoglobin electrophoresis of rare cases were analyzed and identified by PCR combined with reverse dot blot (RBD-PCR), GAP-PCR and DNA sequencing.
Results: Among the 7 patients, one adult patient had normal hemoglobin levels, with slightly decreased mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH). Hb Bart's band was found in 6 neonates by hemoglobin electrophoresis, of which the content of Hb Bart's band in 1 neonate was 15.80%, and the content of Hb Bart's band in the other 5 neonates was 0.30%-0.90%. The results of genetic analysis showed that all the 7 patients had HbA2 : c.96-2A > G (IVS-I-116A > G) mutation, in which 1 case was compounded with - ^SEA deletion.
Conclusion: HbA2 : c.96-2A > G mutation carriers exhibit the phenotype of α-thalassemia, and when the HbA2 :c.96-2A > G mutation is combined with - ^SEA deletion, an intermediate phenotype of anemia is produced.