Objective To analyze the relationship of human leukocyte antigen alleles (HLA-A/B, HLA-DRB/DQB) polymorphism and Eales disease, tuberculosis infection in a Han population in Zunyi city of China. Methods The subjects were analyzed by case control study, which consisted of three groups including Eales disease group (47 patients), pulmonary tuberculosis group (36 patients) and normal control group (100 healthy people). Thirty-nine patients in Eales disease group who had complete history were divided into 4 subgroups according to the history and tuberculin PPD test. Twelve patients with past or present pulmonary tuberculosis were in group A, 27 patients without pulmonary tuberculosis were in group B, 27 patients with positive PPD test were in group C, and 12 patients with negative PPD test were in group D. Fifty-nine alleles of HLA-A/B and HLA-DRB/DQB were analyzed by polymerase chain reaction with sequencespecific primers (PCR-SSP) in all subjects. Odds ratios between each group (OR) and 95% confidence interval (CI) were calculated; Frequency distribution of HLA-A02 gene were analyzed for the group A and the TB group. Results The frequency distribution of HLA-A02 （OR=9.719, OR95% CI:4.377-21.580,P=0.000）and HLA-B07 （OR=11.605, OR95% CI:2.397-56.191,P=0.001）alleles in Eales disease group were obviously higher than that in normal control group, but frequency distribution of HLA-A11（OR=0.495, OR95% CI:0.245-1.000,P=0.048）in Eales disease group was obviously lower than that in normal control group. There was no significant difference in frequency distribution of HLA-A02, HLA-A11 and HLA-B07 alleles between groups A and B, and between groups C and D (P＞0.05). The distribution frequency of HLA-A02, HLA-A24, HLA-B07 and HLA-DRB16 alleles among Eales disease group, pulmonary tuberculosis group and control group was statistically different (P＜0.05). The frequency distribution of HLA-A24 alleles in pulmonary tuberculosis group was lower than that in Eales disease group （chi;2=7.289,P=0.007）, but the frequency distribution of HLA-A02 alleles had no significant difference (OR=0.515,P=0.202) between two groups. Conclusions The alleles of HLA-A02 and HLA-B07 may be genetic predisposing genes of Eales disease, but HLA-A11 alleles may be protective gene in population of Han nationality from Zunyi city. The alleles of HLA-DRB16 and HLA-A02 may be genetic predisposing genes of pulmonay tuberculosis. The alleles of HLA-A02 may be a common susceptible gene for Eales disease and pulmonary tuberculosis. HLA-A11 and HLA-A24 alleles were protective genes of Eales disease and pulmonary tuberculosis respectively.
Epigenetic mechanisms influence gene expression and function without modification of the base sequence of DNA and may generateagenetic phenotype. Epigenetic modifications include DNA methylation, histone modifications, and deployment of noncoding RNA. There is growing evidence that epigenetic mechanisms could playacrucial role in the development of diabetic retinopathy (DR). Molecular biological methods which could maintain mitochondrial homeostasis through the regulation of epigenetic mechanisms may prevent the development of DR. Epigenetic-related treatment modalities will become the new direction of targeted therapy for DR.
Epigenetics has become one of the major research directions of human genome after genome sequencing, and plays an important role in many complex pathophysiological processes such as tumor, biological development, aging and neuropathy. The metabolic memory phenomenon in diabetic retinopathy (DR) suggests that the pathogenesis of DR has a complicated relationship with epigenetic factors. Many studies show the changes and roles of histone modification, DNA methylation and non-coding RNA in the development of DR. However, the current understanding of how epigenetic modifications affect diseases is limited, and most studies on histone modifications have not been carried out in DR. There is still a lot of room for development in epigenetic research on DR. At the same time, epigenetic modification is very complicated, and how to integrate the interaction of different modifications in the development stage of DR is the focus of future research work.
Mycobacterium tuberculosis is the causative agent of human tuberculosis. Through the genotyping of Mycobacterium tuberculosis, we can find the epidemic situation and characteristics of tuberculosis in time, analyze the transmission chain between patients in different jurisdictions, and formulate effective intervention measures in time, to provide a strong basis for clinical diagnosis and treatment. At present, several genotyping techniques for Mycobacterium tuberculosis have their advantages and disadvantages in application. This article reviews the genotyping technology, population genetics and genotyping naming rules of Mycobacterium tuberculosis.
Objective To observe the genetic predisposition of complement C5 gene polymorphisms in proliferative diabetic retinopathy (PDR) in Chongqing Han population. Methods 400 type 2 diabetes (T2D) patients (case group) and 600 age- and sex-matched healthy controls (control group) were enrolled in this study. There were 8 PDR patients in case group. All the subjects were Han ethnic people. The immune-related representative SNP locus of C5 gene including rs2269067, rs7040033, rs7027797 were screened by linkage disequilibrium analysis. Locus rs1017119 was selected by TagSNP and was around the above three loci. Subjects′ peripheral venous blood was collected and DNA was extracted. Genotyping was examined by PCR-restriction fragment length polymorphism method. The level of C5 plasma protein was measured by enzyme-linked immunoabsorbent assay. Results The frequency of GG genotype of rs2269067 was significantly increased in PDR patients in cases group compared with controls (Pc=3.4×10-5, OR=1.87, 95%CI=1.43 - 2.44；P=3.1×10-6). There was no differences in frequency of G, CC and CG genotype of rs2269067 between two groups (P=1.4×10-4, 1.000, 1.0×10-6). There were no differences in frequency of G, CC, CG, GG genotype of rs7040033, rs1017119, and rs7027797 between two groups (P > 0.05). The production of C5 plasma protein was significantly increased in case group as compare with control group (P=0.0004). An increased production of C5 plasma protein was observed in rs2269067 GG genotype cases compared to CG or CC cases (P=0.003, 0.001). Conclusion C5 rs2269067 GG genotype may be associated with the PDR of T2D in Chongqing Han population.
Familial exudative vitreoretinopathy (FEVR) is a hereditary disease with high geneticheterogeneity, including autosomal dominant inheritance, autosomal recessive inheritance, snd X-linked recessive inheritance. So far, six genes have been found to be associated with FEVR: Wnt receptor fizzled protein (FZD4), Norrie disease (NDP), co-receptor low-densitylipoprotein receptor-related protein 5 (LRP5), and tetrasin 12 (TSPANI2), zinc finger protein408 (ZNF408), kinesin family member 11 (KIF11) gene. Among them, FZD4, NDP, LRPS, TSPANI2 and other four genes play an important role in the Norrin/Frizzled 4 signaling pathway. In retinal capillary endothelial cells, Norrin specifically controls the occurrence of ocular capillaries by activating the Norrin/Frizzled 4 signaling pathway. ZNF408 and KIF11 are newly discovered pathogenic genes related to FEVR in the past 5 years. ZNF408 encodes the transcription factor that plays an important role in retinal angiogenesis. KIF11 plays a role in eye development and maintenance of retinal morphology and function.
Objective To investigate the disease-causing gene of Stargardt disease. Method Fifteen patients with Stargardt disease were analyzed with 11 primers of the 11 exons of ABCR gene by using PCR-SSCP and DNA direct sequencing techniques. Results Three newly detected disease-causing mutations were found. Among those mutations, one is a frameshift mutation and others are single base transition. Conclusion This research confirmed that ABCR gene is associated with Stargardt disease, and 3 new mutations of ABCR gene were found. (Chin J Ocul Fundus Dis,2000,16:240-243)