Analysis of Genome-Wide DNA Methylation Differences in Umbilical Cord Blood Nucleated Red Blood Cells Between Term and Preterm Infants / 中国实验血液学杂志

OBJECTIVE@#To analyze the genome-wide DNA methylation differences in umbilical cord blood nucleated red blood cells (NRBCs) between term and preterm infants by using the methylation gene chip technology, and to screen the genes of differential methylation and biological signaling pathways which may be related to the expression of γ-globin gene (HBG).@*METHODS@#Umbilical cord bloods of eight term infants and eight preterm infants were collected, and NRBCs of each sample was isolated, then genome DNA was extracted and bisulfite conversion was performed. The DNA methylation sites were detected by using the Illumina 850K BeadChip. Differential DNA methylation sites were screened, and the function of genes with differential methylation was analyzed by using GO and KEGG enrichment analysis.@*RESULTS@#Compared with the preterm group, 4749 differential DNA methylation sites of term group were screened out, including 4359 hypomethylation sites and 390 hypermethylation sites. GO and KEGG analysis indicated that the function of genes with differential methylation mainly involved in the hemopoietic system, growth and development process, Wnt and Notch signal pathways.@*CONCLUSION@#The differentical methylation sites at genome-wide level in umbilicar cord blood NRBC of term and preterm infants have been obtained, and the signal pathway and genes which possibily related with swiching the expression of γ-globin gene to β-globin gene have been screened-out. This study provide the new targets for studing the mechamism regulating expression of HBG gene.

Effect of Blocking PYR Complex Binding to DNA Site by Peptide Nucleic Acid on γ-Globin Gene Expression / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of blocking polypyrimidine complex binding to DNA site by using peptide nucleic acid (PNA) on γ-globin gene expression.</p><p><b>METHODS</b>PYR-PNA, β-PNA and RS-PNA (random sequence-PNA) were designed and synthesized, then were transfected into K562 cells with the cationic liposome lipofectamine 2000 used as vector. The expression of γ-globin gene at both the transcriptional and translational level was detected by RT-PCR and the Western blot respectively at 24 h, 48 h and 72 h after transfection with PNAs.</p><p><b>RESULTS</b>Compared with RS-PNA and control groups, the expression of γ-globin gene at mRNA and protein levels in PYR-PNA group was significantly up-regulated(P<0.05), especially at 48 h after tranfection, the levels of mRNA and protein in PYR-PNA group were increased by 2.0 and 2.5 times than those in control group, respectively.</p><p><b>CONCLUSION</b>PYR-PNA can significantly up-regulate the expression of γ-globin gene in K562 cells, this study may provide a new research idea for gene therapy of β-thalassemia.</p>

Impact of five genetic polymorphisms on inter-individual variation in warfarin maintenance dose / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the effect of genetic polymorphisms in VKORC1, CYP2C9, GGCX, EPHX1, APOE genes on inter-individual variation in warfarin maintenance dose.</p><p><b>METHODS</b>Two hundred and forty-nine patients with stable warfarin dose were enrolled in this study, and the clinical data and blood samples of the patients were collected. Genotypes for the 5 genes were determined by using PCR and denaturing high performance liquid chromatography (DHPLC) assay. The warfarin maintenance doses were compared among patients with different genotypes of the 5 genes, and a warfarin stable dosing algorithm was derived based on genetic and non-genetic factors.</p><p><b>RESULTS</b>Of the 5 genes, VKORC1, CYP2C9 and GGCX were associated with warfarin stable dose. The multiple linear regression analysis indicated that VKORC1, CYP2C9 and GGCX genes, age and weight, had significant influence on inter-individual variation in warfarin stable dose, which contributed 30.2%, 22.8%, 1.5%, 4.7% and 6.7% respectively. The warfarin stable dosing algorithm acquired from the optimal regression model could explain 57.8% variation in warfarin dose.</p><p><b>CONCLUSION</b>This study suggested that genetic factors are the major determinants of the warfarin maintenance dose, and warfarin stable dosing algorithm may be useful for helping clinicians to prescribe warfarin with greater safety and efficiency.</p>

Identification of a missense mutation in SEDL gene from a Chinese family with X-linked spondyloepiphyseal dysplasia tarda / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the SEDL gene mutation in a Chinese family with X-linked spondyloepiphyseal dysplasia tarda (SEDL) and to establish a genotyping assay for rapid diagnosis of this X-linked recessive disorder.</p><p><b>METHODS</b>Clinical diagnoses were made based on physical examination, radiological examination and pedigree analysis for this family. Four primer pairs flanking the SEDL exons 3-6 including their exon/intron boundaries were designed. A rapid genotyping assay based on denaturing high performance liquid chromatography (DHPLC) was established to screen the point mutations of the SEDL gene. Genomic DNA was extracted by standard methods from 18 members in the three generations of the pedigree and subjected to PCR-denaturing high performance liquid chromatography (PCR-DHPLC) assay followed by direct DNA sequencing.</p><p><b>RESULTS</b>A c.218C>T mutation in exon 4 of the SEDL gene, which resulted in a substitution of serine 218 with leucine, was identified in this family. Among the 18 members, 3 patients, 5 obligate female carriers and 2 unmarried young females were found to have the missense mutation, and other 8 healthy individuals were not detected to carry the mutation, in which genotype-phenotype correlations were well established in each member investigated in this family.</p><p><b>CONCLUSION</b>A c.218C>T missense mutation in the SEDL gene was firstly reported in Chinese population and the results of this study expand the spectrum of SEDL mutations. The PCR-DHPLC assay is a useful tool to rapidly detect the SEDL mutation in clinical and prenatal diagnosis.</p>