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Florent Soubrier – One of the best experts on this subject based on the ideXlab platform.

  • identification of new Polymorphisms of the angiotensin i converting enzyme ace gene and study of their relationship to plasma ace levels by two qtl segregation linkage analysis
    American Journal of Human Genetics, 1996
    Co-Authors: Eric Villard, Laurence Tiret, Sophie Visvikis, Roger Rakotovao, Francois Cambien, Florent Soubrier
    Abstract:

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage desequilibrium (LD) with the ACE insertion/deletion (I/D) Polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new Polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D Polymorphism. These Polymorphisms could be divided into two groups: five Polymorphisms in the 5′ region and three in the coding sequence and the 3′ UTR. Within each group, Polymorphisms were in nearly complete association, whereas Polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D Polymorphism, all Polymorphisms of the 5′ group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the two markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D Polymorphism itself or the newly characterized 4656(CT)2/3 Polymorphism. The second QTL would have a frequency of approximately .20, which is incompatible with any of the yet-identified Polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants.

  • identification of new Polymorphisms of the angiotensin i converting enzyme ace gene and study of their relationship to plasma ace levels by two qtl segregation linkage analysis
    American Journal of Human Genetics, 1996
    Co-Authors: Eric Villard, Laurence Tiret, Sophie Visvikis, Roger Rakotovao, Francois Cambien, Florent Soubrier
    Abstract:

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage disedisequilibrium (LD) with the ACE insertion/deletion (I/D) Polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new Polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D Polymorphism. These Polymorphisms could be divided into two groups: five Polymorphisms in the 5{prime} region and three in the coding sequence and the 3{prime} UTR. Within each group, Polymorphisms were in nearly complete association, whereas Polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D Polymorphism, all Polymorphisms of the 5{prime} group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the twomore » markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D Polymorphism itself or the newly characterized 4656(CT){sub 2/3} Polymorphism. The second QTL would have a frequency of {approximately}.20, which is incompatible with any of the yet-identified Polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants. 30 refs., 1 fig., 6 tabs.« less

Eric Villard – One of the best experts on this subject based on the ideXlab platform.

  • identification of new Polymorphisms of the angiotensin i converting enzyme ace gene and study of their relationship to plasma ace levels by two qtl segregation linkage analysis
    American Journal of Human Genetics, 1996
    Co-Authors: Eric Villard, Laurence Tiret, Sophie Visvikis, Roger Rakotovao, Francois Cambien, Florent Soubrier
    Abstract:

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage desequilibrium (LD) with the ACE insertion/deletion (I/D) Polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new Polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D Polymorphism. These Polymorphisms could be divided into two groups: five Polymorphisms in the 5′ region and three in the coding sequence and the 3′ UTR. Within each group, Polymorphisms were in nearly complete association, whereas Polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D Polymorphism, all Polymorphisms of the 5′ group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the two markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D Polymorphism itself or the newly characterized 4656(CT)2/3 Polymorphism. The second QTL would have a frequency of approximately .20, which is incompatible with any of the yet-identified Polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants.

  • identification of new Polymorphisms of the angiotensin i converting enzyme ace gene and study of their relationship to plasma ace levels by two qtl segregation linkage analysis
    American Journal of Human Genetics, 1996
    Co-Authors: Eric Villard, Laurence Tiret, Sophie Visvikis, Roger Rakotovao, Francois Cambien, Florent Soubrier
    Abstract:

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage disequilibrium (LD) with the ACE insertion/deletion (I/D) Polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new Polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D Polymorphism. These Polymorphisms could be divided into two groups: five Polymorphisms in the 5{prime} region and three in the coding sequence and the 3{prime} UTR. Within each group, Polymorphisms were in nearly complete association, whereas Polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D Polymorphism, all Polymorphisms of the 5{prime} group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the twomore » markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D Polymorphism itself or the newly characterized 4656(CT){sub 2/3} Polymorphism. The second QTL would have a frequency of {approximately}.20, which is incompatible with any of the yet-identified Polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants. 30 refs., 1 fig., 6 tabs.« less

Sophie Visvikis – One of the best experts on this subject based on the ideXlab platform.

  • myeloperoxidase Polymorphisms in brain infarction association with infarct size and functional outcome
    Atherosclerosis, 2003
    Co-Authors: Aline Hoy, Brigitte Leiningermuller, Odette Poirier, Gerard Siest, Marion Gautier, Alexis Elbaz, Pierre Amarenco, Sophie Visvikis
    Abstract:

    Myeloperoxidase (MPO) has been shown to contribute to several diseases and more particularly to atherosclerosis through excessive ROS production via the MPO/H(2)O(2)/Cl(-) oxidation system. The aim of this study was to determine whether there is an association between MPO Polymorphisms and brain infainfarction (BI), one of the main consequences of atherosclerosis. We investigated MPO G-463A and G-129A Polymorphisms in 450 patients with BI confirmed by magnetic resoresonanceging (MRI) and 450 controls of the GENIC (Genetique de l’Infarctus Cerebral) Study. Genotype determination of MPO was performed by polymerase chain reaction and allele-specific oligonucleotide hybridization (ASO). Genotype distributions for each of both MPO Polymorphisms were found to be similar between cases and controls overall, and according to etiologic subtypes or gender. The frequency of the A allele of the G-463A Polymorphism was 22% (95% confidence interval, 19.4 to 24.9) and the frequency of the A allele of the G-129A Polymorphism was 6.8% (95% confidence interval, 5.3 to 8.6). The odds ratio (OR) for BI in carriers of the A allele of the G-129A Polymorphism was 0.92 (95% confidence interval, 0.61 to 1.39), and the OR for BI in carriers of the A allele of the G-463A Polymorphism was 1.15 (95% confidence interval, 0.88 to 1.52). No association between the main risk factors for BI such as hypertension, cholesterol, diabetes and MPO Polymorphisms was found. In analyses restricted to cases, we identified an association between the A allele of the G-129A Polymorphism and the size of the brain infarct (P=0.01). Furthermore, the A allele of the G-463A Polymorphism was associated with a poorer functional short-term outcome as evaluated by the Rankin score (P=0.02). In conclusion, MPO Polymorphisms were associated with the extent of brain damage and the functional outcome rather than with the risk of developing a BI.

  • identification of new Polymorphisms of the angiotensin i converting enzyme ace gene and study of their relationship to plasma ace levels by two qtl segregation linkage analysis
    American Journal of Human Genetics, 1996
    Co-Authors: Eric Villard, Laurence Tiret, Sophie Visvikis, Roger Rakotovao, Francois Cambien, Florent Soubrier
    Abstract:

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage desequilibrium (LD) with the ACE insertion/deletion (I/D) Polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new Polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D Polymorphism. These Polymorphisms could be divided into two groups: five Polymorphisms in the 5′ region and three in the coding sequence and the 3′ UTR. Within each group, Polymorphisms were in nearly complete association, whereas Polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D Polymorphism, all Polymorphisms of the 5′ group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the two markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D Polymorphism itself or the newly characterized 4656(CT)2/3 Polymorphism. The second QTL would have a frequency of approximately .20, which is incompatible with any of the yet-identified Polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants.

  • identification of new Polymorphisms of the angiotensin i converting enzyme ace gene and study of their relationship to plasma ace levels by two qtl segregation linkage analysis
    American Journal of Human Genetics, 1996
    Co-Authors: Eric Villard, Laurence Tiret, Sophie Visvikis, Roger Rakotovao, Francois Cambien, Florent Soubrier
    Abstract:

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage disequilibrium (LD) with the ACE insertion/deletion (I/D) Polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new Polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D Polymorphism. These Polymorphisms could be divided into two groups: five Polymorphisms in the 5{prime} region and three in the coding sequence and the 3{prime} UTR. Within each group, Polymorphisms were in nearly complete association, whereas Polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D Polymorphism, all Polymorphisms of the 5{prime} group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the twomore » markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D Polymorphism itself or the newly characterized 4656(CT){sub 2/3} Polymorphism. The second QTL would have a frequency of {approximately}.20, which is incompatible with any of the yet-identified Polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants. 30 refs., 1 fig., 6 tabs.« less

Kanchan Mukhopadhyay – One of the best experts on this subject based on the ideXlab platform.

  • lack of significant association between 1021c t Polymorphism in the dopamine beta hydroxylase gene and attention deficit hyperactivity disorder
    Neuroscience Letters, 2006
    Co-Authors: Nipa Bhaduri, Kanchan Mukhopadhyay
    Abstract:

    Abstract Recent trends in medications for attention deficit hyperactivity disorder (ADHD) suggest that norepinephrine (NE) deficiency may contribute to the disease etiology. Dopamine beta hydroxylase (DBH) is the key enzyme which converts dopamine to NE and since DBH gene is considered a major quantitative trait locus for plasma DBH activity, genetic Polymorphism may lead to altered NE neurotransmission. Several Polymorphisms including a 5′ flanking −1021C→T Polymorphism, was reported to be associated with changed DBH activity and an association between −1021C→T Polymorphism with ADHD was observed in Han Chinese children. We have carried out family-based studies with three Polymorphisms in the DBH gene, −1021C→T Polymorphism, exon 2*444g/a and intron 5 TaqI RFLP, to explore their association with Indian ADHD cases. Allele and genotype frequency of these Polymorphisms in ADHD cases were compared with that of their parents and a control group. Haplotypes obtained were analyzed for linkage disedisequilibrium (LD). Haplotype-based haplotype relative risk analysis and transmission disequilibrium test showed lack of significant association between transmission of the Polymorphisms and ADHD. A haplotype comprising of allele 1 of all Polymorphisms showed a slight positive trend towards transmission from parents to ADHD probands. Strong LD was observed between *444g/a and TaqI RFLP in all the groups. However, low D ′ values and corresponding log of odds scores in the control group as compared to the ADHD families indicated that, the incidence of the two Polymorphisms being transmitted together could be higher in ADHD families.

  • analysis of Polymorphisms in the dopamine beta hydroxylase gene association with attention deficit hyperactivity disorder in indian children
    Indian Pediatrics, 2005
    Co-Authors: Nipa Bhaduri, Swagata Sinha, Anindita Chattopadhyay, Prasanta Kumar Gangopadhyay, Manoranjan Singh, Kanchan Mukhopadhyay
    Abstract:

    OBJECTIVE To study the association of Attention Deficit Hyperactivity Disorder (ADHD) and Polymorphism in the dopamine beta hydroxylase (DBH) gene in Indian ADHD cases. SUBJECTS Forty one ADHD cases were diagnosed as per the DSM-IV-TR criteria and evaluated by Conners Parents and Teachers Rating Scale and Wechslers Intelligence Scale for Children. METHODS Genomic DNA was amplified for exon 2 *444g/a and intron 5 (Taq I) Polymorphism in the DBH gene followed by restriction fragment length Polymorphism (RFLP) analysis. Haplotype-based haplotype relative risk (HHRR) was analyzed to ascertain the transmission pattern of these two Polymorphisms in ADHD cases. Linkage disedisequilibrium (LD) between the two Polymorphisms was calculated using EH+ and 2LD programs. RESULTS In the limited number of samples analyzed, a slight increase in transmission of the 444a allele in ADHD subjects was observed for DBH 444g/a. The intron 5 (Taq I) Polymorphism showed no significant association with ADHD in these cases. Strong disequilibrium was observed between DBH444g/a and intron 5 (Taq I) Polymorphism. CONCLUSION This is the first molecular genetic study on ADHD in Indian subjects exploring transmission of Polymorphisms in the DBH gene. Preliminary investigation shows a trend towards association between the transmission of DBH444a allele and ADHD. No association was noticed between transmission of intron 5 (Taq I) Polymorphism and ADHD in the Indian subjects. Presence of strong LD may point towards co-segregation of these two Polymorphisms more often than expected.

Roger Rakotovao – One of the best experts on this subject based on the ideXlab platform.

  • identification of new Polymorphisms of the angiotensin i converting enzyme ace gene and study of their relationship to plasma ace levels by two qtl segregation linkage analysis
    American Journal of Human Genetics, 1996
    Co-Authors: Eric Villard, Laurence Tiret, Sophie Visvikis, Roger Rakotovao, Francois Cambien, Florent Soubrier
    Abstract:

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage desequilibrium (LD) with the ACE insertion/deletion (I/D) Polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new Polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D Polymorphism. These Polymorphisms could be divided into two groups: five Polymorphisms in the 5′ region and three in the coding sequence and the 3′ UTR. Within each group, Polymorphisms were in nearly complete association, whereas Polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D Polymorphism, all Polymorphisms of the 5′ group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the two markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D Polymorphism itself or the newly characterized 4656(CT)2/3 Polymorphism. The second QTL would have a frequency of approximately .20, which is incompatible with any of the yet-identified Polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants.

  • identification of new Polymorphisms of the angiotensin i converting enzyme ace gene and study of their relationship to plasma ace levels by two qtl segregation linkage analysis
    American Journal of Human Genetics, 1996
    Co-Authors: Eric Villard, Laurence Tiret, Sophie Visvikis, Roger Rakotovao, Francois Cambien, Florent Soubrier
    Abstract:

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage disequilibrium (LD) with the ACE insertion/deletion (I/D) Polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new Polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D Polymorphism. These Polymorphisms could be divided into two groups: five Polymorphisms in the 5{prime} region and three in the coding sequence and the 3{prime} UTR. Within each group, Polymorphisms were in nearly complete association, whereas Polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D Polymorphism, all Polymorphisms of the 5{prime} group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the twomore » markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D Polymorphism itself or the newly characterized 4656(CT){sub 2/3} Polymorphism. The second QTL would have a frequency of {approximately}.20, which is incompatible with any of the yet-identified Polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants. 30 refs., 1 fig., 6 tabs.« less