[Molecular mechanism of 101A>G and 845G>A mutations of RHD gene responsible for a weak RhD].

OBJECTIVE: To explore the molecular basis for an individual with a rare weak D phenotype.

METHODS: Regular serological assaying and indirect antiglobulin testing (IAT) were performed to characterize the RhD blood group. Mutations of the RHD gene were screened by polymerase chain reaction (PCR), reverse transcription PCR and DNA sequencing. Amplified cDNA product was TA cloned and subjected to haplotype analysis.

RESULTS: The RhD blood group of the proband was determined as weak D. The result of PCR amplification showed that all of the 10 exons of the RHD gene were present. Heterozygote status of 101A/G and 845A/G were determined by gDNA and cDNA sequencing. After TA cloning and haplotype sequencing, two alleles 101A>G mutation (weak D 101G ) and 845G>A mutation (weak D type 15) were revealed.

CONCLUSION: 101A>G and 845G>A mutations are responsible for the low expression of RhD antigen on the red blood cells of the proband, which has resulted in a weak D phenotype.