[Molecular Diagnosis and Pedigree Analysis of Rare Mutations in Non-coding Region of HBA2 Gene]

To perform molecular diagnosis and pedigree analysis for one case with α-thalassemia who does not conform to the genetic laws, and explore the effects of a newly discovered rare mutation (HBA2:c.*12G>A) on clinical phenotypes.

Blood samples of the proband and her family members were collected for blood routine analysis, and the hemoglobin components were analyzed by capillary electrophoresis. The common α- and β-globin gene loci in Chinese population were detected by conventional techniques (Gap-PCR, RDB-PCR). The α-globin gene sequences (HBA1, HBA2) were analyzed by Sanger sequencing.

By analyzing the test results of proband and her family members, the genotype of the proband was -α^3.7/HBA2:c.*12G>A, her father was HBA2:c.*12G>A heterozygous mutation carrier.

This study identifies a rare α-globin gene mutation (HBA2:c.*12G>A) that has not been reported before. It is found that heterozygous mutation carriers present with static α-thalassemia.