Abstract: Objective To identify a rare α-thalassemia gene mutation in a family from south China and perform a pedigree analysis and genetic diagnosis of hemoglobin H (HbH) disease caused by this mutation. Methods Peripheral blood samples were collected from the family members for analysis of the hematological phenotype and routine test of thalassemia genes. DNA sequencing was carried out for samples that showed genotype and phenotype inconsistency. Results A rare α-thalassemia *92A>G gene mutation was detected within this family. The proband and his sister were confirmed to have non-deletional HbH disease with a --SEA/α*92A>Gα genotype. The proband’s brother was confirmed to have an α-thalassemia trait with the genotype of -α3.7/α*92A>Gα. The proband’s father was identified as an α-thalassemia silent carrier with the genotype of αα/α*92A>Gα. Conclusion A rare α-thalassemia *92A>G gene mutation was identified for first time in south China. The description of the basic phenotypic characteristics of α-thalassemia trait and silent carrier caused by this mutation enriches the α-thalassemia gene mutation spectrum in Chinese population and helps in population screening, clinical molecular diagnosis and genetic counseling.