A novel nonsense mutation in RHAG gene responsible for Rh_null phenotype in a Chinese individual

Rh_null is a rare autosomal recessive phenotype, which is characterized by the lack of Rh antigen expression on the red blood cells (RBCs). Rh_null of the regulator type is caused by RHAG mutation. In this study, a novel nonsense mutation in RHAG gene was identified in a Chinese Rh_null individual.

Rh phenotypes of the Rh_null individual and his family members were typed by standard serological methods. DNA sequences of all ten exons of RHAG gene were analyzed using genomic DNA by polymerase chain reaction (PCR) and direct-sequencing.

Serological testing results showed a D-C-c-E-e- phenotype in the proband. Molecular analyses revealed a 540C>A mutation in exon 4 of RHAG gene was present at the homozygous state in the proband. His parents were heterozygous for the mutation, and his brother didn't carry the mutation. The 540C>A mutation was nonsense mutation, which led to a premature stop codon (Tyr180stop).

These results indicated that the 540C>A nonsense mutation in RHAG gene caused the regulator type of Rh_null phenotype in a Chinese individual. Our results contributed to a greater understanding of the genetic mechanisms of Rh_null phenotype.