Molecular study of two novel RHD alleles and pedigree analysis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the segregation of two novel RHD alleles in Chinese pedigrees.</p><p><b>METHODS</b>The Rh antigens of the samples were identified by using monoclonal antibodies. The 10 exons of the RHD gene for the 2 probands and their family members were amplified separately and sequenced. The parents of proband 2 were analyzed by sequence specific primer-polymerase chain reaction (SSP-PCR).</p><p><b>RESULTS</b>The two probands were RhD negative and the RHD was D/d type. After alignment with the nucleotide sequence in GenBank, a deletion of nucleotide C at position 78 in exon 1 of proband 1 was detected, and her sister also had the deletion, which was confirmed by sequencing. The sequencing results of proband 2 showed a 10 nucleotide deletion in exon 8 as well as a RHD 520 G to A mutation in exon 4. The results of SSP-PCR and sequencing showed that the proband's mother also carried RHD 520 G to A and RHD 1080 del 10 mutation, which was transmitted to proband 2. The sequences of the novel alleles have been submitted to GenBank (accession No. GQ477180 and GU362076).</p><p><b>CONCLUSION</b>The two novel RHD alleles, RHD 78delC and RHD 520 G to A+1080 del 10, were both pseudo genes and stably transmitted.</p>

Correlation between DNA methylation of the ABO gene promoter CpG island and leukemia / 中国实验血液学杂志

Recent studies have found that ABO blood group antigen is also closely related to the onset and development of many diseases. More and more attention is being paid to the decrease of A/B blood group antigen caused by some tumors. This study was purpose to investigate the correlation between DNA methylation of the ABO gene promoter CpG island and leukemia. The relative contents of ABH antigen on the surface of RBC from kinds of blood disease patients and healthy individuals were detected by using flow cytometry and confocal laser scanning microscopy. The DNA sequences and CpG methylation of ABO gene promoter in patients with hematopathy and healthy individuals, as well as the -102 site methylation of ABO gene promoter in patients with hematopathy and healthy individuals were detected by PCR and MSP-PCR respectively. The results showed that RBC from leukemia patients displayed different degree of A/B antigen decrease. The sequences of ABO gene promotor of patients with hematopathy were not different from healthy individuals indicating high conservation of promoter sequences. Comparison of sequences between patients with hematopathy and healthy individual indicated that CpG islands on ABO gene promoter either from blood disease patients or from healthy individual had no methylated site in AA patients, but C residues at position -102, -101, -100, -99 and -97 on the promoter of ABO gene in AML, CML, ALL and some MDS patients were methylated. It is concluded that methylation of CpG islands in promoter of ABO gene may result in AB antigen decrease in patients with leukemia. The methylation sites -102, -101, -100, -99 and -97 may be specific for leukemia. The methylation of site -102 can be used as a molecular marker in differential diagnosis for leukemias.