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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Minor cartilage collagens:characterization of the human COL9A1, COL9A2 and COL11A2 genes and the mouse Col11a2 gene. Identification of a mutation in the COL11A2 gene in a family with non-ocular Stickler syndrome

Vuoristo, M. (Mirka) 05 December 2003 (has links)
Abstract Collagens IX, a non-fibrillar collagen, and XI, a fibrillar collagen, are minor components of cartilage collagen fibrils, which form a supportive meshwork in the cartilage extracellular matrix (ECM). Collagens IX and XI are known to be present also in other tissues, including the vitreous body of the eye, the intervertebral disc, the inner ear, and various tissues during embryonic development. Collagen IX is suggested to act as a macromolecular bridge between collagen fibrils and other ECM molecules, and it may be important for the cohesive and compressive properties of cartilage, as well as the long-term stability of articular cartilage. Collagen XI is speculated to have a role in regulating the fibril diameter, and it may participate in interactions with other ECM components. However, the role of neither collagen IX nor XI has been confirmed yet. As important but minor components of the cartilage ECM, collagens IX and XI are excellent candidates for relatively mild chondrodysplasias and even milder disease phenotypes involving cartilaginous tissues, such as non-syndromic hearing loss. There are in fact many reports describing defects in the genes for collagens IX and XI in patients with a variety of chondrodysplasias, including multiple epiphyseal dysplasia, Stickler syndrome, Marshall syndrome and otospondylomegaepiphyseal dysplasia. In order to screen the minor cartilage collagen genes for mutations, it is essential to know their gene structures. Therefore, the complete structures of the human COL9A1, COL9A2 and COL11A2 genes were characterized in this study. Also, to facilitate the analysis of the 5' region of the COL11A2 gene, the cDNA and partial genomic structure of the mouse Col11a2 gene were defined. The information obtained in this study was utilized in the mutation analysis of a family with non-ocular Stickler syndrome. The COL11A2 gene was analyzed with conformation sensitive gel electrophoresis (CSGE) and sequencing, and a heterozygous single-nucleotide mutation causing a premature termination codon was found in the affected family members. Studying the effect of the mutation on the RNA revealed that the nonsense mutation caused the skipping of a 54-bp exon, presumably through a pathway called nonsense-associated altered splicing.
2

Genetic defects of collagen XI:the role of a minor cartilage collagen in chondrodysplasias, oral cleft defects and osteoarthrosis

Melkoniemi, M. (Miia) 17 May 2005 (has links)
Abstract Collagen XI is a minor component of articular cartilage collagen fibrils together with collagen IX. They are in close functional relationship with the major cartilage collagen II. Collagen XI has been suggested to play a role in regulating the diameter of collagen II fibrils. Together these collagens form a supportive framework in the extracellular matrix. Besides articular cartilage, these three collagens can also be found in the vitreous body of the eye, the intervertebral disc, the inner ear and in various tissues during embryonic development. As the major cartilage collagen, collagen II has been studied quite extensively. Several syndromes ranging from lethal to milder ones have been shown to result from collagen II gene defects. Far less is known about defects in genes coding for the minor cartilage collagens, IX and XI. By identifying mutations in the coding genes and observing the resulting phenotypes, the function and importance of these genes start to unravel. The goal of this study was to provide more information about collagen XI. As a quantatively minor cartilage component, it is a good candidate for mild disease phenotypes. Collagen XI gene mutations have been shown to cause relatively mild phenotypes, such as Stickler and Marshall syndromes and non-syndromic hearing loss. Seven families with a recessive chondrodysplasia, otospondylomegaepiphyseal dysplasia (OSMED), were analysed for mutations in COL11A2. This study showed that OSMED is typically caused by the absence of the α2(XI) chains. Sixty-two patients with isolated Robin sequence, cleft palate or micrognathia were analysed for COL11A2 gene mutations. Six unique nucleotide changes were found that are likely to associate with the phenotype. The results showed that collagen XI gene defects can play a role in the etiology of oral clefting, but are not common causes of these phenotypes. Altogether 72 unrelated osteoarthrosis (OA) patients and one family with OA were analysed for mutations in genes coding for collagens II, IX and XI. Eighteen percent of them were found to have a unique sequence variation. An association analysis of OA patients failed to reveal any common predisposing alleles in these genes.
3

Estudo das mutações no gene COL2A1 em uma coorte de pacientes com displasias esqueléticas do grupo colagenopatia tipo II segundo critérios clínico-radiológicos / Study of mutations in the COL2A1 gene in a cohort of patients with skeletal dysplasias of type 2 collagenopathy group according to clinical and radiological criteria

Silveira, Karina da Costa, 1989- 24 August 2018 (has links)
Orientadores: Denise Pontes Cavalcanti, Luciana Cardoso Bonadia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T20:03:03Z (GMT). No. of bitstreams: 1 Silveira_KarinadaCosta_M.pdf: 2998560 bytes, checksum: 286fe3d0377e879226faf2cb88d92569 (MD5) Previous issue date: 2014 / Resumo: As displasias esqueléticas ou osteocondrodisplasias são doenças genéticas que afetam o crescimento e o desenvolvimento do tecido ósseo e cartilaginoso produzindo, em geral, baixa estatura. Mutações em heterozigose no gene COL2A1 são responsáveis por uma série de displasias esqueléticas conhecidas como colagenopatias do tipo II que geralmente apresentam um padrão espondiloepifisário típico. Apesar das mutações no COL2A1 serem, em geral, "privadas", o estudo molecular desse gene em pacientes com fenótipos sugestivos de colagenopatia do tipo II pode contribuir seja para um melhor entendimento das colagenopatias do tipo II seja para refinar, quando possível, a correlação genótipo-fenótipo. O objetivo desse estudo foi investigar o gene COL2A1 numa coorte de pacientes com fenótipo de colagenopatia do tipo II de modo a melhorar o conhecimento sobre essas colagenopatias. Foram estudados 33 pacientes com fenótipo de colagenopatia do tipo II. A análise molecular foi feita por sequenciamento automático bidirecional direto do gene COL2A1, começando pelos domínios relacionados a cada fenótipo seguido de sequenciamento completo das regiões codificantes do gene quando as primeiras foram negativas. Foram identificadas alterações potencialmente deletérias em heterozigose em 23 dos 33 pacientes (69,7%): 18 alterações do tipo missense (11 inéditas, 7 descritas), 4 alterações que alteram sítio de splice (2 inéditas, 2 descritas) e uma deleção inédita. Das mutações do tipo missense encontradas, duas foram recorrentes em 5 pacientes: p.G594E e p.R989C. Ambas as mutações recorrentes foram associadas a fenótipos graves: a p.R989C foi observada em displasia espondiloepifisária congênita (SEDC) grave enquanto que a p.G594E foi associadaa 2 recém-nascidos com fenótipo de SEDC-letal. Para todas as mutações novas, a análise in silico, estudo em controles e/ou dos pais confirmaram a patogenicidade de todas elas. Concluindo, os resultados deste estudo permitiram a identificação de 14 mutações novas no gene COL2A1 e um melhor refinamento da correlação genótipo-fenótipo / Abstract: Skeletal dysplasias are genetic disorders that affect the growth and development of the bone and cartilage tissues producing, in general, short stature. Heterozygous mutations in the COL2A1 gene are responsible for a number of skeletal dysplasias that usually exhibit a pattern spondyloepiphyseal and are called type II collagenopathies. Although the mutations in COL2A1 are usually privates, molecular studies of this gene in patients with suggestive phenotypes can contribute to a better understanding of the type II collagenopathies. The aim of this study was to sequence the COL2A1 in a cohort of patients with type II collagenopathy phenotypes in order to refine the knowledge regarding the genotype-phenotype correlation. Thus, 33 patients with suggestive phenotype were studied. The molecular analysis was performed by automated Sanger bidirectional sequencing of the COL2A1 gene, starting with the domains related to each phenotype followed by whole sequencing of the gene coding regions when the first ones were negative. Potentially deleterious changes in heterozygosity were identified in 23 of 33 patients (69.7 %): 18 missense changes (11 undescribed), 4 changes that modify the splice site (2 undescribed) and a new deletion. The pathogenicity of the undescribed changes were confirmed by in silico analysis, study of control individuals and/or of the respective parents. Among the found missense mutations, two were recurrent and associated with severe phenotypes. These mutations, p.G594E and p.R989C, were found in five patients. The R989C change was observed in three children presenting a phenotype of spondyloepiphyseal dysplasia congenita (SEDC), which follow up showed a pattern of severe SEDC featured by severe disproportioned short stature with coxa vara and kyphoscoliosis. The G594E change was associated with two newborns presenting also a SEDC phenotype, however with lethal evolution. In conclusion, the results of this study allowed the identification of 14 new mutations in COL2A1 gene and a better refinement of the genotype-phenotype correlation / Mestrado / Ciencias Biomedicas / Mestra em Ciências Médicas
4

Metacarpophalangeal pattern profile analysis in hypochondroplasia, dyschondrosteosis and Turner syndrome /

Laurencikas, Evaldas, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
5

Estudo do gene SHOX em casos de discondrosteose de Léri Weill e displasia mesomélica de Langer / Study of SHOX gene in cases of Leri-Weill dyschondrosteosis and Langer mesomelic dysplasia

Lima, Renata de 16 August 2018 (has links)
Orientadores: Andréa Trevas Maciel Guerra, Maricilda Palandi de Mello / Tese (doutorado) - Universidade Estadual de Campinas. Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-16T03:18:52Z (GMT). No. of bitstreams: 1 Lima_Renatade_D.pdf: 4015661 bytes, checksum: e48a1ea1afcdb807a4d9186f4bb5777c (MD5) Previous issue date: 2010 / Resumo: A Discondrosteose de Leri-Weill (DLW), caracterizada por baixa estatura, encurtamento mesomélico dos membros e deformidade de Madelung, deve-se a alterações no gene SHOX, localizado na região pseudoautossômica dos cromossomos sexuais e que atua como fator de transcrição. Alterações em um dos alelos são encontradas em casos de baixa estatura com ou sem DLW, e em ambos os alelos na Displasia Mesomélica de Langer (DML), na qual há alterações esqueléticas mais graves. Há variação fenotípica na DLW, atribuída ao envolvimento de outros genes ou a alterações nas regiões reguladoras à jusante ao gene. No presente estudo, realizou-se a investigação do gene SHOX de 10 pacientes com DLW e um com DML por meio de análises de microssatélites, PCR em tempo real, análise de MLPA e sequenciamento direto. Essas análises permitiram confirmar a etiologia genética do quadro apresentado por sete pacientes, dos quais três apresentavam deleção total ou parcial de um dos alelos. Em um destes pacientes a clinica foi associada a mutação de ponto (IVS3+21G>A no íntron 3), outro paciente (DML) a deleção dos dois alelos, outros pacientes (DLW) a deleção na região downstream do gene, outros dois mutações de ponto (c.439C>A no éxon 3 e c.523delC no éxon 4), outro a deleção (c.523delC) associada a mutação na região 5'UTR. Quatro outros pacientes apresentaram alterações de patogenicidade ainda indefinida: mutações não descritas na região 5'UTR, que poderia interferir no processo de tradução do gene (dois casos), e deleção das regiões referentes às sondas 8, 10 e 12 na análise de MLPA (um caso) e outro caso com relação à deleção da sonda SHOX reg. Os resultados mostram a grande heterogeneidade alélica associada à DLW e indicam a necessidade de que a investigação molecular nesses casos seja ampla, permitindo um diagnóstico molecular mais preciso. / Abstract: Leri-Weill Dyschondrosteosis (LWD) is characterized by short stature, mesomelic shortening of members and Madelung deformity. It results from changes in the SHOX gene, located in the pseudoautosomal region of the sex chromosomes. The protein it codes acts as a transcription factor. Changes in one SHOX allele are found in cases of short stature with or without LWD, whereas Langer Mesomelic Dysplasia (LMD), in which more serious skeletal disorders occur, results from alterations in both alleles. There is phenotypic heterogeneity in LWD, attributed to the possible involvement of other genes, or to changes in regulatory regions downstream of the gene. In the present study, the SHOX gene and the chromosomal SHOX gene region were evaluated in 11 patients with LWD and LMD by using microsatellite PCR, real time PCR analysis, MLPA analysis, and direct sequencing. Those tests confirmed the genetic etiology of the clinical characteristics in seven patients. Three of them carried alleles bearing a partial or total deletion of the SHOX gene, one of which bearing a mutation located in intron 3 (IVS3+21G>A) that has not been described previously; the patient with LMD carried SHOX gene deletion in both alleles; and another had a deletion in the dpwnstream region of the gene. Two patients bore mutations that have not been described previously in exons 3 (C.4390A, Arg147Ser) and 4 (c.523delC, Gln175Lisfs44x219). The later was also associated with a mutation in 5'UTR. Four other patients showed nucleotide changes and deletions of undefined pathogenicity: novel mutations in the 5'UTR, which might interfere with the translation process of the gene (two cases), and deletion of regions related to the probes 8, 10 and 12 in the MLPA analysis (one case) and deletion oh probe SHOX reg. Results showed great molecular heterogeneity associated with LWD, and pointed out the need of a more detailed research to allow more accurate molecular diagnosis. / Doutorado / Ciencias Biomedicas / Doutor em Ciências Médicas
6

Novas contribuições sobre a correlação genótipo-fenótipo do grupo FGFR3 a partir do estudo de uma coorte de pacientes com fenótipo típico ou sugestivo / New contributions about the genotype-phenotype correlation of the FGFR3 group from the study of a cohort of patients with typical or suggestive phenotype

Kanazawa, Thatiane Yoshie, 1988- 24 August 2018 (has links)
Orientadores: Denise Pontes Cavalcanti, Luciana Cardoso Bonadia / Texto em português e inglês / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T19:05:42Z (GMT). No. of bitstreams: 1 Kanazawa_ThatianeYoshie_M.pdf: 1904408 bytes, checksum: 8b54672e34f366d597d94eb97bfafa4d (MD5) Previous issue date: 2014 / Resumo: Entre as osteocondrodisplasias (OCD) destacam-se as displasias esqueléticas do grupo 1 (FGFR3) devido à sua alta frequência. Nesse grupo, além das displasias com fenótipo característico e considerável correlação genótipo-fenótipo, como a acondroplasia (Ach) e a displasia tanatofórica (DT), está a hipocondroplasia (Hch), cujo fenótipo em geral é mais leve, apresenta grande variabilidade clínico-radiológica e heterogeneidade etiológica. O objetivo desse estudo foi sequenciar o gene FGFR3 numa coorte de pacientes com fenótipo típico ou sugestivo. A análise molecular foi feita por sequenciamento direto, começando pelos hot spots e, seguindo com o sequenciamento completo do gene quando os primeiros foram negativos. Foram incluídos 63 pacientes na casuística: 30 Ach, 7 Hch, 10 Hch?, 13 DT-I e 3 DT-II. Dentre os casos de Ach, todos apresentaram a mutação mais comumente associada à Ach (p.G380R), inclusive um paciente com fenótipo atípico e suspeita de mosaicismo somático, não comprovado, devido à assimetria corporal. Dentre os casos de Hch, todos os sete apresentaram a mutação mais comum para este fenótipo (p.N540K) inclusive dois pacientes com uma Hch grave com manifestações clínicas e radiológicas no período neonatal e dez pacientes, diagnosticados como uma Hch duvidosa (Hch?) por apresentarem baixa estatura com alguns sinais radiológicos, não foi encontrada mutação, sendo que em cinco casos, o sequenciamento não foi concluído. Três mutações diferentes, que ocorrem com maior frequência, foram identificadas entre os casos de DT-I, a p.R248C em sete pacientes, entre eles um paciente atípico por apresentar maior sobrevida, p.S249C em três e a p.Y373C em dois. Em todos os casos de DT-II, como esperado, foi encontrada a única mutação até então descrita para este fenótipo (p.K650E). Os resultados deste estudo permitiram a identificação de casos interessantes, ressaltaram a ótima correlação genótipo-fenótipo do grupo FGFR3 e reforçaram a importância da investigação molecular do gene FGFR3 nos casos com fenótipos duvidosos ou atípicos / Abstract: Among osteochondrodysplasias (OCD) stand out the skeletal dysplasias group 1 (FGFR3) due to its high frequency. In this group, besides the conditions with considerable characteristic phenotype and genotype-phenotype correlation, such as achondroplasia (Ach) and thanatophoric dysplasia (TD), there is hypochondroplasia (HCH), whose phenotype is generally milder, with a large clinical and radiological variability and etiological heterogeneity. The aim of this study was to sequence the FGFR3 gene in a cohort of patients with typical or suggestive phenotype. Molecular analysis was performed by direct sequencing, starting with the hot spots, and following with the complete sequencing of the gene when the first were negative. In this sample, 63 patients were included: 30 Ach, 7 Hch, 10 Hch?, 13 DT-I and 3 DT-II. Among the Ach cases, all exhibit the most common mutation associated with Ach (p.G380R), including one patient with an atypical phenotype, with suspicious of somatic mosaicism, not confirmed, due to body asymmetry. Among the Hch cases, all the seven patients showed the most common mutation for this phenotype (p.N540K) including two patients with severe Hch with clinical and radiological manifestations in the neonatal period and ten patients, diagnosed as a doubtful Hch (Hch?), because of their low stature with some radiological signs, no mutation was found, and in five cases, sequencing was not completed. Three different mutations, which occur more frequently, were identified among the DT-I cases, p.R248C in seven patients, including an atypical patient with a long-term survival, p.S249C in three and p.Y373C in two. In all DT-II cases, as expected, the only mutation described so far for this phenotype (p.K650E) was found. The results of this study allowed the identification of interesting cases, emphasized the great genotype-phenotype correlation of FGFR3 group and reinforced the importance of molecular investigation of the FGFR3 gene in cases with doubtful or atypical phenotypes / Mestrado / Ciencias Biomedicas / Mestra em Ciências Médicas

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