{"title":"人MHC的RCCX模块之间的不平等交叉导致C4A和C4B基因之间存在CYP21B基因和tenascin TNXB/TNXA-RP2重组。","authors":"K L Rupert, R M Rennebohm, C Y Yu","doi":"10.1159/000019099","DOIUrl":null,"url":null,"abstract":"<p><p>The RCCX module of the human MHC class III region is comprised of four genes arranged in tandem: RP, complement C4, steroid 21-hydroxylase (CYP21), and tenascin X (TNX). Variations in the number and genes of the RCCX modules may lead to genetic and/or autoimmune diseases. Restriction fragment length polymorphism (RFLP) analysis was utilized to determine the RCCX modular variation in patients with juvenile rheumatoid arthritis (JRA). In JRA patient L1, RFLP analysis suggested the presence of a bimodular RCCX structure containing both C4A long and C4B short genes, yet missing the markers for the CYP21A and TNXA genes usually located between the C4A and C4B genes. The 7.5-kb genomic fragment spanning the CYP21-TNX-RP2 genes was cloned and sequenced, revealing that a genetic recombination occurred between TNXA of a bimodular RCCX chromosome and TNXB of a monomodular RCCX chromosome. This recombination results in a new MHC haplotype with a CYP21B gene and a TNXB/TNXA-RP2 recombinant between the two C4 genes. Elucidation of the breakpoint region provides further evidence for the instability of the MHC class III gene region as a result of the RCCX modular variation.</p>","PeriodicalId":77124,"journal":{"name":"Experimental and clinical immunogenetics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000019099","citationCount":"38","resultStr":"{\"title\":\"An unequal crossover between the RCCX modules of the human MHC leading to the presence of a CYP21B gene and a tenascin TNXB/TNXA-RP2 recombinant between C4A and C4B genes in a patient with juvenile rheumatoid arthritis.\",\"authors\":\"K L Rupert, R M Rennebohm, C Y Yu\",\"doi\":\"10.1159/000019099\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The RCCX module of the human MHC class III region is comprised of four genes arranged in tandem: RP, complement C4, steroid 21-hydroxylase (CYP21), and tenascin X (TNX). Variations in the number and genes of the RCCX modules may lead to genetic and/or autoimmune diseases. Restriction fragment length polymorphism (RFLP) analysis was utilized to determine the RCCX modular variation in patients with juvenile rheumatoid arthritis (JRA). In JRA patient L1, RFLP analysis suggested the presence of a bimodular RCCX structure containing both C4A long and C4B short genes, yet missing the markers for the CYP21A and TNXA genes usually located between the C4A and C4B genes. The 7.5-kb genomic fragment spanning the CYP21-TNX-RP2 genes was cloned and sequenced, revealing that a genetic recombination occurred between TNXA of a bimodular RCCX chromosome and TNXB of a monomodular RCCX chromosome. This recombination results in a new MHC haplotype with a CYP21B gene and a TNXB/TNXA-RP2 recombinant between the two C4 genes. Elucidation of the breakpoint region provides further evidence for the instability of the MHC class III gene region as a result of the RCCX modular variation.</p>\",\"PeriodicalId\":77124,\"journal\":{\"name\":\"Experimental and clinical immunogenetics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1999-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1159/000019099\",\"citationCount\":\"38\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Experimental and clinical immunogenetics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1159/000019099\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Experimental and clinical immunogenetics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1159/000019099","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 38
摘要
人类MHC III类区域的RCCX模块由四个基因串联组成:RP、补体C4、类固醇21-羟化酶(CYP21)和tenascin X (TNX)。RCCX模块数量和基因的变化可能导致遗传和/或自身免疫性疾病。采用限制性内切片段长度多态性(RFLP)分析确定幼年类风湿性关节炎(JRA)患者RCCX模块变异。在JRA患者L1中,RFLP分析提示存在包含C4A长基因和C4B短基因的双模RCCX结构,但缺失通常位于C4A和C4B基因之间的CYP21A和TNXA基因的标记。研究人员克隆并测序了跨越CYP21-TNX-RP2基因的7.5 kb基因组片段,发现双模RCCX染色体的TNXA与单模RCCX染色体的TNXB之间发生了基因重组。这种重组产生了一个新的MHC单倍型,在两个C4基因之间有一个CYP21B基因和一个TNXB/TNXA-RP2基因重组。断点区域的阐明为MHC III类基因区域的不稳定性提供了进一步的证据,这是RCCX模块化变异的结果。
An unequal crossover between the RCCX modules of the human MHC leading to the presence of a CYP21B gene and a tenascin TNXB/TNXA-RP2 recombinant between C4A and C4B genes in a patient with juvenile rheumatoid arthritis.
The RCCX module of the human MHC class III region is comprised of four genes arranged in tandem: RP, complement C4, steroid 21-hydroxylase (CYP21), and tenascin X (TNX). Variations in the number and genes of the RCCX modules may lead to genetic and/or autoimmune diseases. Restriction fragment length polymorphism (RFLP) analysis was utilized to determine the RCCX modular variation in patients with juvenile rheumatoid arthritis (JRA). In JRA patient L1, RFLP analysis suggested the presence of a bimodular RCCX structure containing both C4A long and C4B short genes, yet missing the markers for the CYP21A and TNXA genes usually located between the C4A and C4B genes. The 7.5-kb genomic fragment spanning the CYP21-TNX-RP2 genes was cloned and sequenced, revealing that a genetic recombination occurred between TNXA of a bimodular RCCX chromosome and TNXB of a monomodular RCCX chromosome. This recombination results in a new MHC haplotype with a CYP21B gene and a TNXB/TNXA-RP2 recombinant between the two C4 genes. Elucidation of the breakpoint region provides further evidence for the instability of the MHC class III gene region as a result of the RCCX modular variation.