Molecular mechanism of 101A>G and 845G>A mutations of RHD gene responsible for a weak RhD / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular basis for an individual with a rare weak D phenotype.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Study of a case with homozygous 35C>T and 658C>T mutations of FUT1 gene leading to a para-Bombay phenotype / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular mechanism for a case with para-Bombay phenotype caused by α-1,2-fucosyltransferase (FUT1) gene mutations.</p><p><b>METHODS</b>Blood phenotype of the propositus was determined by standard serological testing. Polymerase chain reaction-sequence specific primer (PCR-SSP) and direct sequencing of PCR product were used to analyze its ABO genotype. The PCR product of FUT1 gene was sequenced and analyzed.</p><p><b>RESULTS</b>The phenotype of the propositus was initially detected as para-Bombay A type. Direct sequencing of ABO gene showed that the genotype of the proband was A101/O01 (261G/del), which was consistent with the result of PCR-SSP. Two homo-mutations, 35C>T and 658C>T, were detected in the FUT1 gene by sequencing, and the genotype was determined as h(35T+658T)/h(35T+658T).</p><p><b>CONCLUSION</b>h(35T+658T)/h(35T+658T) is responsible for the para-Bombay phenotype of the propositus. The genotype is rare even in para-Bombay populations.</p>