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1.
成骨不全(Osteogenesis imperfecta,OI)是一种由于Ⅰ型胶原形成障碍,导致骨脆性增强为主要症状的常染色体显性遗传性疾病。临床上主要表现为骨质脆弱、蓝巩膜、耳聋和中等程度的关节畸形等症状。成骨不全基因分别定位于17q21.31-q22和7q22.1,其致病基因分别为COL1A1和COL1A2。对一常染色体显性遗传的成骨不全家系进行连锁分析,在COL1A1遗传位点发现紧密连锁(LOD=9.31;θ=.00)。突变检测发现在COL1A1基因第26内含子5′端剪接位点处存在一由GT转换为AT的致病突变,该突变引起的异常剪接是导致成骨不全的致病原因之一。 相似文献
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一成骨不全家系的COL1A1基因突变检测 总被引:7,自引:0,他引:7
成骨不全(Osteogenesisimperfecta,OI)是一种由于Ⅰ型胶原形成障碍,导致骨脆性增强为主要症状的 常染色体显性遗传性疾病。临床上主要表现为骨质脆弱、蓝巩膜、耳聋和中等程度的关节畸形等症状。成骨不全 基因分别定位于17q21.31 q22和7q22.1,其致病基因分别为COL1A1和COL1A2。对一常染色体显性遗传的 成骨不全家系进行连锁分析,在COL1A1遗传位点发现紧密连锁(LOD=9.31;θ=.00)。突变检测发现在 COL1A1基因第26内含子5′端剪接位点处存在一由GT转换为AT的致病突变,该突变引起的异常剪接是导致成 骨不全的致病原因之一。 相似文献
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常、X染色体遗传及显、隐性的判断 总被引:1,自引:1,他引:0
对控制性状的基因在常染色体还是在X染色体上,是显性基因还是隐性基因进行准确判断,是遗传学考试经常出现的试题。这种题不仅考查学生的基本生物学知识,而且考查学生的综合运用能力,方法如下: 1常染色体、伴X遗传方式的判断1.1正反交法这种方法适合杂交亲本是纯合的情况。对正交和反交的结果进行比较,若正交反交结果相同,与性别无关,是常染色体的遗传;若正交反交的结果不同,其中一种杂交后代的某一性状(或2个性状)和性别明显相关,则是伴X遗传。 相似文献
5.
单基因遗传病(简称单基因病)是指受1对等位基因控制的遗传病,它可以分为5类:Y染色体遗传病,X 染色体上的显性遗传病,X染色体上的隐性遗传病,常染色体上的显性遗传病,常染色体上的隐性遗传病。这5类单基因病的判断及其相关概率的计算是遗传和变异这一章的重点,亦是难点所在。现总结一些规律供参考。 相似文献
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病理性近视的家系研究 总被引:1,自引:0,他引:1
为了探讨我国病理性近视的遗传模式,对90个病理性近视大家系进行了分离分析。简单分离分析采用先验法和SEGRAN-B软件,进行拟合优度卡方检验,比较实际分离比与理论分离比的符合程度;复合分离分析运用SAGE-REGD软件进行孟德尔遗传模型(主基因、显性、隐性、共显性)和非孟德尔遗传模型(非传递、环境、一般)的拟合。结果显示,婚配类型为A*N的家系符合常染色体显性遗传,散发概率为13.8%,婚配类型为N*N的家系符合常染色体隐性遗传,散发概率为16.3%,但常染色体显性遗传不能除外,复合分离分析接受孟德尔遗传的显性、隐性、共显性和主基因模型,共显性模型的可能性最大,基因频率为0.21442999。因此,我国病理性近视存在常染色体显性和隐性遗传模式,并有一定比例的散发病例,具有遗传异质性。 相似文献
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摘要 目的:从收集的两个来自中国的常染色体显性遗传性的先天性核性白内障家系中,确定与其白内障致病相关的基因遗传突变位点,以明确致病原因。方法:首先通过记录详细的家系成员患病史、白内障手术史和其他临床资料,通过眼科常用的视力、眼压、裂隙灯检查以及眼底检查,排除家系成员的其他眼科疾病。并在取得家系成员的知情同意下,从家系成员的外周血白细胞中提取基因组DNA,最后通过对已知的先天性白内障候选基因进行测序,以筛选出致病的突变位点。并通过软件分析突变位点的高保守性。结果:通过眼科常用的裂隙灯仪器检查,两个家系的先天性白内障临床表型均被确定为核性白内障类型。通过对先天性白内障就候选基因直接测序,发现了在晶状体蛋白γD基因(CRYGD)中,核苷酸位置c.193处,发现了一个G>A的突变。该突变与两个家系中所有患病的个体共分离,未患病的成员和120名无关对照成员中未观察到该突变。共保守分析表明,一个高度保守的区域序列位于CRYGD的第65位密码子(P.65)。结论:在两个常染色体显性遗传性先天性核性白内障的中国家系中发现了CRYGD基因的一个新突变D65N,这是第一次在CRYGD基因的第193位核苷酸处,发现突变G→A。导致了第65位密码子的天冬氨酸(D)突变为天冬酰胺(N),这些结果提供了强有力的证据,证明了晶状体蛋白γD基因(CRYGD)是先天性白内障的致病基因,并与核性的先天性白内障临床表型高度相关。 相似文献
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《现代生物医学进展》2014,(17):I0002-I0002
<正>日前,温州医科大学报告说,他们成功地揭示了导致隐性遗传视网膜色素变性的一个全新致病基因SLC7A14。据悉,这是迄今为止由我国学者独立发现的第一个隐性致病基因。其相关研究成果已于3月27日发表在英国《自然》杂志旗下综合性子刊《自然-通讯》(Nature Communications)上,题为《导致常染色体隐性视网膜色素变性的新致病基因SLC7A14》。视网膜色素变性是眼科中最常见的遗传病,由于已知致病基因超过70个,因而精确诊断和分型一直是临床上的大难题,而基因诊断是开展 相似文献
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为了揭示成骨不全(Osteogenesis imperfecta,OI)Ⅰ型家系的分子遗传学发生机制,文章采用PCR-DNA直接测序法,对患儿COL1A1和COL1A2基因共103个外显子(E)进行突变检测。结果显示:患儿COL1A1基因未发现任何病理性突变,而在COL1A2基因E19内发现一新的杂合错义突变(p.G316C),该突变来自其父,而其母正常,其他表型正常的6位亲属也均未发现该突变;通过DHPLC(Denaturing high performance uid chromatography)筛检,发现患儿与其父均有异常双峰,而其母和所有正常对照均为正常单峰;通过ASA(Allele specific amplification)筛检,患儿与其父均有391 bp的特异扩增带,而其母和所有正常对照均未见特异扩增带;保守性分析结果显示,该突变位点所在甘氨酸在进化上具有高度保守性;SIFT和Poly Phen-2软件预测结果显示,新突变造成的结果是"有害的"和"很可能有害"。上述结果均说明COL1A2基因c.946GT/p.G316C新突变是导致OI-Ⅰ型的致病性突变,是引起患儿发病的真正内因。患儿父母若再次孕育,可在孕早期进行产前基因诊断或孕前期进行PGD(Preimplantation genetic diagnosis)予以防患。 相似文献
11.
Gajko-Galicka A 《Acta biochimica Polonica》2002,49(2):433-441
Osteogenesis imperfecta (OI), commonly known as "brittle bone disease", is a dominant autosomal disorder characterized by bone fragility and abnormalities of connective tissue. Biochemical and molecular genetic studies have shown that the vast majority of affected individuals have mutations in either the COL1A1 or COL1A2 genes that encode the chains of type I procollagen. OI is associated with a wide spectrum of phenotypes varying from mild to severe and lethal conditions. The mild forms are usually caused by mutations which inactivate one allele of COL1A1 gene and result in a reduced amount of normal type I collagen, while the severe and lethal forms result from dominant negative mutations in COL1A1 or COL1A2 which produce structural defects in the collagen molecule. The most common mutations are substitutions of glycine residues, which are crucial to formation and function of the collagen triple helix, by larger amino acids. Although type I collagen is the major structural protein of both bone and skin, the mutations in type I collagen genes cause a bone disease. Some reports showed that the mutant collagen can be expressed differently in bone and in skin. Since most mutations identified in OI are dominant negative, the gene therapy requires a fundamentally different approach from that used for genetic-recessive disorders. The antisense therapy, by reducing the expression of mutant genes, is able to change a structural mutation into a null mutation, and thus convert severe forms of the disease into mild OI type I. 相似文献
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Xiran Wang Yu Pei Jingtao Dou Juming Lu Jian Li Zhaohui Lv 《Genetics and molecular biology》2015,38(1):1-7
Osteogenesis imperfecta (OI) is a family of genetic disorders associated with bone
loss and fragility. Mutations associated with OI have been found in genes encoding
the type I collagen chains. People with OI type I often produce insufficient α1-chain
type I collagen because of frameshift, nonsense, or splice site mutations in
COL1A1 or COL1A2. This report is of a Chinese
daughter and mother who had both experienced two bone fractures. Because skeletal
fragility is predominantly inherited, we focused on identifying mutations in
COL1A1 and COL1A2 genes. A novel mutation in
COL1A1, c.700delG, was detected by genomic DNA sequencing in the
mother and daughter, but not in their relatives. The identification of this mutation
led to the conclusion that they were affected by mild OI type I. Open reading frame
analysis indicated that this frameshift mutation would truncate α1-chain type I
collagen at residue p263 (p.E234KfsX264), while the wild-type protein would contain
1,464 residues. The clinical data were consistent with the patients’ diagnosis of
mild OI type I caused by haploinsufficiency of α1-chain type I collagen. Combined
with previous reports, identification of the novel mutation
COL1A1-c.700delG in these patients suggests that
additional genetic and environmental factors may influence the severity of OI. 相似文献
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Witecka J Auguściak-Duma AM Kruczek A Szydło A Lesiak M Krzak M Pietrzyk JJ Männikkö M Sieroń AL 《Journal of applied genetics》2008,49(3):283-295
Osteogenesis imperfecta (OI) is a bone dysplasia caused by mutations in theCOL1A1 andCOL1A2 genes. Although the condition has been intensely studied for over 25 years and recently over 800 novel mutations have been
published, the relation between the location of mutations and clinical manifestation is poorly understood. Here we report
missense mutations inCOL1A1 of several OI patients. Two novel mutations were found in the D1 period. One caused a substitution of glycine 200 by valine
at the N-terminus of D1 in OI type I/IV, lowering collagen stability by 50% at 34°C. The other one was a substitution of valine
349 by phenylalanine at the C-terminus of D1 in OI type I, lowering collagen stability at 37.5°C. Two other mutations, reported
before, changed amino residues in D4. One was a lethal substitution changing glycine 866 to serine in genetically identical
twins with OI type II. That mutated amino acid was near the border of D3 and D4. The second mutation changed glycine 1040
to serine located at the border of D4 and D0.4, in a proband manifesting OI type III, and lowered collagen stability at 39°C
(2°C lower than normal). Our results confirm the hypothesis on a critical role of the D1 and D4 regions in stabilization of
the collagen triple-helix. The defect in D1 seemed to produce a milder clinical type of OI, whereas the defect in the C-terminal
end of collagen type caused the more severe or lethal types of OI. 相似文献
15.
Background
Osteogenesis imperfecta (OI) is a rare bone disorder. In 90% of cases, OI is caused by mutations in the COL1A1/2 genes, which code procollagen α1 and α2 chains. The main aim of the current research was to identify the mutational spectrum of COL1A1/2 genes in Estonian patients. The small population size of Estonia provides a unique chance to explore the collagen I mutational profile of 100% of OI families in the country.Methods
We performed mutational analysis of peripheral blood gDNA of 30 unrelated Estonian OI patients using Sanger sequencing of COL1A1 and COL1A2 genes, including all intron-exon junctions and 5′UTR and 3′UTR regions, to identify causative OI mutations.Results
We identified COL1A1/2 mutations in 86.67% of patients (26/30). 76.92% of discovered mutations were located in the COL1A1 (n = 20) and 23.08% in the COL1A2 (n = 6) gene. Half of the COL1A1/2 mutations appeared to be novel. The percentage of quantitative COL1A1/2 mutations was 69.23%. Glycine substitution with serine was the most prevalent among missense mutations. All qualitative mutations were situated in the chain domain of pro-α1/2 chains.Conclusion
Our study shows that among the Estonian OI population, the range of collagen I mutations is quite high, which agrees with other described OI cohorts of Northern Europe. The Estonian OI cohort differs due to the high number of quantitative variants and simple missense variants, which are mostly Gly to Ser substitutions and do not extend the chain domain of COL1A1/2 products.16.
《Endocrine practice》2019,25(3):230-241
Objective: Osteogenesis imperfecta (OI) is a group of heritable fragile bone diseases, and the majority are caused by pathogenic variants in the COL1A1 and COL1A2 genes. We sought to identify the genetic causes and phenotypes of OI in Chinese patients without COL1A1 or COL1A2 mutations.Methods: Twenty-three patients who were diagnosed with sporadic OI but did not carry COL1A1/2 mutations were recruited, and their genomic DNA was analyzed using targeted next-generation sequencing of rare OI-related genes. The resulting damaging mutations in the probands and their parents were verified using Sanger sequencing. Moreover, the efficacy of long-term bisphosphonate treatment was evaluated in proband 1.Results: Compound heterozygous variants in the WNT1 and TMEM38B genes were identified in proband 1 and proband 2, respectively. A heterozygous mutation in the P4HB gene was identified in proband 3, and a hemizygous mutation in PLS3 was identified in proband 4. The unaffected parents of the probands (except the father of proband 4) with mutations in the WNT1, TMEM38B, and PLS3 genes were heterozygous carriers of each of the variants, respectively. Notably, proband 3 had the characteristic exophthalmos, flat nasal bridge and flat, wide forehead. None of the patients presented with dentinogenesis imperfecta or hearing loss. Furthermore, bisphosphonates exerted beneficial effects on proband 1, who carried the WNT1 mutations, by increasing bone mineral density Z-score, reshaping the compressed vertebrae and decreasing the fracture risk.Conclusion: We identified novel mutations and expanded the spectrum of phenotypes and genotypes of the extremely rare disorder OI.Abbreviations: BMD = bone mineral density; MIM = Mendelian Inheritance in Man; OI = osteogenesis imperfecta; PDI = protein disulfide isomerase 相似文献
17.
Kaneko H Kitoh H Matsuura T Masuda A Ito M Mottes M Rauch F Ishiguro N Ohno K 《Human genetics》2011,130(5):671-683
Autosomal dominant osteogenesis imperfecta (OI) is caused by mutations in COL1A1 or COL1A2. We identified a dominant missense mutation, c.3235G>A in COL1A1 exon 45 predicting p.G1079S, in a Japanese family with mild OI. As mutations in exon 45 exhibit mild to lethal phenotypes,
we tested if disruption of an exonic splicing cis-element determines the clinical phenotype, but detected no such mutations. In the Japanese family, juvenile-onset hyperuricemia
cosegregated with OI, but not in the previously reported Italian and Canadian families with c.3235G>A. After confirming lack
of a founder haplotype in three families, we analyzed PRPSAP1 and PRPSAP2 as candidate genes for hyperuricemia on chr 17 where COL1A1 is located, but found no mutation. We next resequenced the whole exomes of two siblings in the Japanese family and identified
variable numbers of previously reported hyperuricemia-associated SNPs in ABCG2 and SLC22A12. The same SNPs, however, were also detected in normouricemic individuals in three families. We then identified two missense
SNVs in ZPBP2 and GPATCH8 on chromosome 17 that cosegregated with hyperuricemia in the Japanese family. ZPBP2 p.T69I was at the non-conserved region and was predicted to be benign by in silico analysis, whereas GPATCH8 p.A979P was at a highly conserved region and was predicted to be deleterious, which made p.A979P a conceivable candidate
for juvenile-onset hyperuricemia. GPATCH8 is only 5.8 Mbp distant from COL1A1 and encodes a protein harboring an RNA-processing domain and a zinc finger domain, but the molecular functions have not been
elucidated to date. 相似文献
18.
David P. Dimasi Jern Y. Chen Alex W. Hewitt Sonja Klebe Richard Davey John Stirling Elizabeth Thompson Robin Forbes Tiong Y. Tan Ravi Savarirayan David A. Mackey Paul R. Healey Paul Mitchell Kathryn P. Burdon Jamie E. Craig 《Human genetics》2010,127(1):33-44
Osteogenesis imperfecta (OI) is a rare connective tissue disorder caused by mutations in the type I collagen genes, COL1A1 and COL1A2, and is characterised by low bone mass and bone fragility. In this study, we explored the relationship between type 1 collagen genes and the quantitative trait central corneal thickness (CCT). CCT was measured in a cohort of 28 Australian type I OI patients and mean CCT was found to be significantly lower compared to a normal population (P < 0.001). We then investigated CCT and corneal collagen fibril diameter and density in a mouse model of OI with a col1a2 mutation. Mean CCT was significantly lower in mutant mice (P = 0.002), as was corneal collagen fibril diameter (P = 0.034), whilst collagen fibril density was significantly greater in mutants (P = 0.034). Finally, we conducted a genetic study to determine whether common single nucleotide polymorphisms (SNPs) in COL1A1 and COL1A2 are associated with CCT variation in the normal human population. Polymorphism rs2696297 (P = 0.003) in COL1A1 and a three SNP haplotype in COL1A2 (P = 0.007) were all significantly associated with normal CCT variation. These data implicate type 1 collagen in the determination of CCT in both OI patients and normal individuals. This provides the first evidence of quantitative trait loci that influence CCT in a normal population and has potential implications for investigating genes involved in glaucoma pathogenesis, a common eye disease in which the severity and progression is influenced by CCT. 相似文献
19.
Cord Drgemüller Doreen Becker Adrian Brunner Bianca Haase Patrick Kircher Frank Seeliger Michael Fehr Ulrich Baumann Kerstin Lindblad-Toh Tosso Leeb 《PLoS genetics》2009,5(7)
Osteogenesis imperfecta (OI) is a hereditary disease occurring in humans and dogs. It is characterized by extremely fragile bones and teeth. Most human and some canine OI cases are caused by mutations in the COL1A1 and COL1A2 genes encoding the subunits of collagen I. Recently, mutations in the CRTAP and LEPRE1 genes were found to cause some rare forms of human OI. Many OI cases exist where the causative mutation has not yet been found. We investigated Dachshunds with an autosomal recessive form of OI. Genotyping only five affected dogs on the 50 k canine SNP chip allowed us to localize the causative mutation to a 5.82 Mb interval on chromosome 21 by homozygosity mapping. Haplotype analysis of five additional carriers narrowed the interval further down to 4.74 Mb. The SERPINH1 gene is located within this interval and encodes an essential chaperone involved in the correct folding of the collagen triple helix. Therefore, we considered SERPINH1 a positional and functional candidate gene and performed mutation analysis in affected and control Dachshunds. A missense mutation (c.977C>T, p.L326P) located in an evolutionary conserved domain was perfectly associated with the OI phenotype. We thus have identified a candidate causative mutation for OI in Dachshunds and identified a fifth OI gene. 相似文献