Abstract:

A rare case of delta-thalassemia gene mutation was reported. Blood routine examination showed that both mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were decreased, and that hemoglobin (Hb) was in critical value. Hemoglobin electrophoresis showed that hemoglobin A₂ (HbA₂) was decreased significantly. The common alpha and beta thalassemia gene test suggested --^SEA/αα. Due to the significant decrease of HbA₂, the suspected carriers of hemoglobin subunit delta (HBD) gene were analyzed. Therefore, the HBD mutation types were further analyzed by Sanger sequencing. DNA sequencing revealed that the patient carried Codon98(-GTG;+A) heterozygous mutant gene, the international nomenclature as HBDc.295_297delGTGinsA. The low level of HbA₂ in this case was due to the mutation of HBD. HBDc.295_297delGTGinsA is a rare type of gene mutations in the Chinese population.

Key words: delta-Globins, Genes, Mutation, Hemoglobin A₂, Case reports