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1.
Phys Chem Chem Phys ; 25(11): 8168-8179, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36880275

RESUMO

We report the existence in NaLa(SO4)2·H2O of a displacive phase transition under 200 K from the nonpolar P3121 to the polar P31 space group. This phase transition was predicted by density functional theory based calculations and experimentally confirmed from infrared spectroscopy and X-ray diffraction. The A2 polar irreducible representation is the primary order parameter. The structural water and hydrogen bonding are the mechanism driving the phase transition. The piezoelectric properties of this new P31 phase have been investigated by first principles based calculations. The highest piezoelectric-strain constants in the zero Kelvin limit are predicted for the d12 and d41 elements with values about 3.4 pC N-1. This compound could be interesting as piezoelectric actuator for cryogenic applications.

2.
Phys Rev Lett ; 126(10): 106001, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33784165

RESUMO

Extreme pressures and temperatures are known to drastically affect the chemistry of iron oxides, resulting in numerous compounds forming homologous series nFeOmFe_{2}O_{3} and the appearance of FeO_{2}. Here, based on the results of in situ single-crystal x-ray diffraction, Mössbauer spectroscopy, x-ray absorption spectroscopy, and density-functional theory+dynamical mean-field theory calculations, we demonstrate that iron in high-pressure cubic FeO_{2} and isostructural FeO_{2}H_{0.5} is ferric (Fe^{3+}), and oxygen has a formal valence less than 2. Reduction of oxygen valence from 2, common for oxides, down to 1.5 can be explained by a formation of a localized hole at oxygen sites.

3.
Prev Med ; 111: 170-176, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29499214

RESUMO

Despite recognition that parents are critical stakeholders in childhood obesity prevention, obesity research has overwhelmingly focused on mothers. In a recent review, fathers represented only 17% of parent participants in >600 observational studies on parenting and childhood obesity. The current study examined the representation of fathers in family interventions to prevent childhood obesity and characteristics of interventions that include fathers compared with those that only include mothers. Eligible studies included family-based interventions for childhood obesity prevention published between 2008 and 2015 identified in a recent systematic review. Data on intervention characteristics were extracted from the original review. Using a standardized coding scheme, these data were augmented with new data on the number of participating fathers/male caregivers and mothers/female caregivers. Out of 85 eligible interventions, 31 (37%) included mothers and fathers, 29 (34%) included only mothers, 1 (1%) included only fathers, and 24 (28%) did not provide information on parent gender. Of the interventions that included fathers, half included 10 or fewer fathers. Across all interventions, fathers represented a mere 6% of parent participants. Father inclusion was more common in interventions targeting families with elementary school-aged children (6-10 years) and those grounded in Ecological Systems Theory, and was less common in interventions focused on very young children (0-1 years) or the prenatal period and those targeting the sleep environment. This study emphasizes the lack of fathers in childhood obesity interventions and highlights a particular need to recruit and engage fathers of young children in prevention efforts.


Assuntos
Pai/estatística & dados numéricos , Poder Familiar , Obesidade Infantil/prevenção & controle , Criança , Humanos , Mães/estatística & dados numéricos
4.
J Vet Pharmacol Ther ; 40(6): 618-628, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28387027

RESUMO

Acetylsalicylic acid (ASA, aspirin) is an antiplatelet medication used for prevention of thromboembolism. Effects of ASA appear to vary widely between dogs, but the underlying mechanisms are not understood. The Multiplate analyzer is a newer form of whole-blood impedance aggregometry recently validated for use in healthy dogs. A method utilizing this instrument to measure ASA effects on platelet function has not been established. The goals of this study were to establish reference ranges for the Multiplate in healthy dogs and secondly, to develop a technique to determine the in vitro concentration of ASA needed to cause 50% inhibition of platelet aggregation (IC50). Reference ranges established from 40 dogs at multiple test times for three agonists were consistent with previously published values. In vitro IC50 values were calculated using the sigmoid Emax model in 20 healthy dogs on two occasions to determine individual repeatability. Calculated in vitro IC50 demonstrated four ASA response groups: responder (n = 16), poor responder (n = 1), variable responder (n = 2), and nonresponder (n = 1). Multiplate within-assay variability was  <10% for area under the curve (AUC), and between-assay baseline AUC variability was  <15%. The described technique allowed for determination of an in vitro IC50 for ASA in dogs using a multiple electrode impedance aggregometer.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Plaquetas/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Aspirina/administração & dosagem , Cães , Relação Dose-Resposta a Droga , Impedância Elétrica , Feminino , Masculino , Valores de Referência
5.
Genes Immun ; 17(5): 305-12, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27278126

RESUMO

To identify genes and biologically relevant pathways associated with risk to develop multiple sclerosis (MS), the Genome-Wide Association Studies noise reduction method (GWAS-NR) was applied to MS genotyping data. Regions of association were defined based on the significance of linkage disequilibrium blocks. Candidate genes were cross-referenced based on a review of current literature, with attention to molecular function and directly interacting proteins. Supplementary annotations and pathway enrichment scores were generated using The Database for Annotation, Visualization and Integrated Discovery. The candidate set of 220 MS susceptibility genes prioritized by GWAS-NR was highly enriched with genes involved in biological pathways related to positive regulation of cell, lymphocyte and leukocyte activation (P=6.1E-15, 1.2E-14 and 5.0E-14, respectively). Novel gene candidates include key regulators of NF-κB signaling and CD4+ T helper type 1 (Th1) and T helper type 17 (Th17) lineages. A large subset of MS candidate genes prioritized by GWAS-NR were found to interact in a tractable pathway regulating the NF-κB-mediated induction and infiltration of pro-inflammatory Th1/Th17 T-cell lineages, and maintenance of immune tolerance by T-regulatory cells. This mechanism provides a biological context that potentially links clinical observations in MS to the underlying genetic landscape that may confer susceptibility.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Loci Gênicos , Ativação Linfocitária/genética , Esclerose Múltipla/genética , NF-kappa B/metabolismo , Transdução de Sinais/genética , Estudos de Casos e Controles , Estudo de Associação Genômica Ampla , Humanos , NF-kappa B/genética
6.
Mol Psychiatry ; 20(12): 1588-95, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25687773

RESUMO

We investigated the genetic overlap between Alzheimer's disease (AD) and Parkinson's disease (PD). Using summary statistics (P-values) from large recent genome-wide association studies (GWAS) (total n=89 904 individuals), we sought to identify single nucleotide polymorphisms (SNPs) associating with both AD and PD. We found and replicated association of both AD and PD with the A allele of rs393152 within the extended MAPT region on chromosome 17 (meta analysis P-value across five independent AD cohorts=1.65 × 10(-7)). In independent datasets, we found a dose-dependent effect of the A allele of rs393152 on intra-cerebral MAPT transcript levels and volume loss within the entorhinal cortex and hippocampus. Our findings identify the tau-associated MAPT locus as a site of genetic overlap between AD and PD, and extending prior work, we show that the MAPT region increases risk of Alzheimer's neurodegeneration.


Assuntos
Doença de Alzheimer/genética , Doença de Parkinson/genética , Proteínas tau/genética , Idoso , Idoso de 80 Anos ou mais , Alelos , Apolipoproteínas E/genética , Encéfalo/patologia , Cromossomos Humanos Par 17 , Feminino , Loci Gênicos , Pleiotropia Genética , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
7.
Scand J Med Sci Sports ; 26(2): 235-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26648587

RESUMO

The King-Devick test appears to be a promising tool in screening for concussions. However, limited evidence exists on the baseline associations between the K-D test and age and baseline screening tools used after concussion. Additionally, there are no published reference values for the K-D test in high school football players. The K-D test, the Balance Error Scoring System, and the Limits of Stability (LOS) test were administered to 157 high school football players. Additionally, a subsample of 62 participants completed the test twice to examine the reliability of K-D test. There was no relationship between the K-D test and the BESS, or the reaction time and directional control of LOS test. Students aged between 16 and 18 years demonstrated faster K-D test performance compared to students between 13 and 15 years of age. However, there was no association between K-D test and history of concussion. The reliability of the K-D test was (ICC2,1 = 0.89), and the minimal detectable change was 6.10 s. Normative reference values for high school football players are presented in this study.


Assuntos
Atenção , Concussão Encefálica/diagnóstico , Testes Diagnósticos de Rotina/normas , Futebol Americano/lesões , Movimentos Sacádicos , Fala , Adolescente , Fatores Etários , Humanos , Masculino , Equilíbrio Postural , Valores de Referência , Reprodutibilidade dos Testes , Estados Unidos
8.
Clin Exp Allergy ; 45(9): 1406-11, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25867098

RESUMO

BACKGROUND: Vocal cord dysfunction (VCD) typically involves abnormal adduction of the vocal cords during inspiration, mimics the symptoms of asthma and leads to the prescription of ineffective medications. OBJECTIVE: We aimed to develop a clinical tool to monitor symptoms and response to treatment in confirmed VCD. METHODS: We collated symptoms of VCD from focus groups comprising patients and healthcare professionals; phrases describing these symptoms were assessed for face validity and internal correlation and rated for importance. The resultant 12-item questionnaire (VCDQ) rated the impact of each on a 5-point Likert scale (total score range 12-60) and was tested for reliability, concurrent validity and performance in 31 patients with endoscopically confirmed VCD (± asthma), 29 asthmatics with no history of VCD and 14 healthy controls. We assessed response to speech and language therapy and the minimal important difference by measuring the VCDQ pre- and post- therapy in a 20 new patients. RESULTS: The VCDQ had excellent test-retest reliability and differentiated VCD vs. healthy (Mann-Whitney U-test: z = -5.390, P < 0.001) and asthma (z = -5.730, P < 0.001). All patients improved post-therapy, assessed both by a global rating of change score (GRCS) and by the VCDQ [median (IQR) score pre-therapy 50.5 (48.0 - 54.8), post-therapy 35.0 (29.3 - 41.8), P < 0.001]. The minimal important difference in the VCDQ associated with a rating of 'minimally better' on the GRCS was 4 points. CONCLUSIONS AND CLINICAL RELEVANCE: The VCDQ is a valid and responsive tool suitable for measuring changes in symptoms in patients with VCD. It also gives insight into which symptoms are important to patients and could guide future therapy refinements. Future assessments of novel therapies for this condition should use an appropriately validated tool such as the VCDQ to measure response.


Assuntos
Asma , Monitorização Fisiológica/métodos , Inquéritos e Questionários , Disfunção da Prega Vocal , Adulto , Idoso , Asma/patologia , Asma/fisiopatologia , Asma/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Disfunção da Prega Vocal/patologia , Disfunção da Prega Vocal/fisiopatologia , Disfunção da Prega Vocal/terapia
9.
Phys Chem Chem Phys ; 17(37): 24262-74, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26325490

RESUMO

A synthetic high-silica mordenite (HS-MOR) has been compressed in both non-penetrating (silicone oil, s.o.) and penetrating [methanol : ethanol : water (16 : 3 : 1) (m.e.w.), water : ethanol (3 : 1) (w.e.), and ethylene glycol (e.gl.)] pressure transmitting media (PTM). In situ high-pressure (HP) synchrotron X-ray powder diffraction (XRPD) experiments allowed the unit cell parameters to be followed up to 1.6, 1.8, 8.4, and 6.7 GPa in s.o., w.e., m.e.w., and e.gl., respectively. Moreover, e.gl. was also used as a PTM in in situ HP Raman and ex situ IR experiments. The structural refinement of HS-MOR compressed in e.gl. at 0.1 GPa - the lowest investigated pressure - revealed the presence of 3.5 ethylene glycol molecules per unit cell. The infrared spectrum of the recovered sample, after compression to 1 GPa, is consistent with the insertion of ethylene glycol molecules in the pores. XRPD and Raman spectroscopy experiments performed under pressure indicated the insertion of a small number of guest molecules. Ethylene glycol is partially retained inside mordenite upon pressure release. A symmetry lowering was observed in s.o. above 0.8 GPa, while above 1.6 GPa the patterns indicated a rapid loss of long range order. From ambient pressure (Pamb) to 1.6 GPa, a high cell volume contraction (ΔV = -9.5%) was determined. The patterns collected with penetrating PTM suggested the penetration of guest molecules into the porous host matrix, starting from a very low P regime. The entrapment of PTM molecules inside micropores contributes to the stiffening of the structure and, as a consequence, to the decrease of the compressibility with respect to that measured in s.o. From the structural point of view, HS-MOR reacts to compression and to the penetration of different guest species with appropriate framework deformations. Interestingly, ethylene glycol is partially retained inside mordenite upon pressure release, which is of importance for potential application of this composite material.

10.
Inorg Chem ; 53(8): 3985-90, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24716664

RESUMO

Relaxor ferroelectric perovskites are highly polarizable and can exhibit giant coupling between elastic strain and an applied electric field. Here, we report an in situ extended X-ray absorption fine structure (EXAFS) study of a PbZn1/3Nb2/3O3 (PZN) single crystal as a function of the electric field. We show that the strong dipoles in the NbO6 octahedra bonds are aligned along the four ⟨011⟩ directions close to the orientation of the electric field, while a small reversible polar shift occurs for Zn in the direction of the electric field, i.e., positive or negative. This reversible Zn-O polar shift is proposed to play an important role in both the "easy" switching of the ferroelectric polarization and the giant piezoelectric effect in PZN.

11.
Hum Genet ; 132(11): 1213-21, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23793441

RESUMO

Previous evidence has shown that Parkinson disease (PD) has a heritable component, but only a small proportion of the total genetic contribution to PD has been identified. Genetic heterogeneity complicates the verification of proposed PD genes and the identification of new PD susceptibility genes. Our approach to overcome the problem of heterogeneity is to study a population isolate, the mid-western Amish communities of Indiana and Ohio. We performed genome-wide association and linkage analyses on 798 individuals (31 with PD), who are part of a 4,998 member pedigree. Through these analyses, we identified a region on chromosome 5q31.3 that shows evidence of association (p value < 1 × 10(-4)) and linkage (multipoint HLOD = 3.77). We also found further evidence of linkage on chromosomes 6 and 10 (multipoint HLOD 4.02 and 4.35 respectively). These data suggest that locus heterogeneity, even within the Amish, may be more extensive than previously appreciated.


Assuntos
Amish/genética , Loci Gênicos , Doença de Parkinson/genética , Cromossomos Humanos Par 10/genética , Cromossomos Humanos Par 5/genética , Cromossomos Humanos Par 6/genética , Biologia Computacional , Ligação Genética , Predisposição Genética para Doença , Genoma Humano , Estudo de Associação Genômica Ampla/métodos , Genótipo , Humanos , Indiana , Ohio , Linhagem , Polimorfismo de Nucleotídeo Único
12.
Clin Genet ; 84(2): 167-74, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23621901

RESUMO

Primary open angle glaucoma (POAG) is a genetically and phenotypically complex disease that is a leading cause of blindness worldwide. Previously we completed a genome-wide scan for early-onset POAG that identified a locus on 9q22 (GLC1J). To identify potential causative variants underlying GLC1J, we used targeted DNA capture followed by high throughput sequencing of individuals from four GLC1J pedigrees, followed by Sanger sequencing to screen candidate variants in additional pedigrees. A mutation likely to cause early-onset glaucoma was not identified, however COL15A1 variants were found in the youngest affected members of 7 of 15 pedigrees with variable disease onset. In addition, the most common COL15A1 variant, R163H, influenced the age of onset in adult POAG cases. RNA in situ hybridization of mouse eyes shows that Col15a1 is expressed in the multiple ocular structures including ciliary body, astrocytes of the optic nerve and cells in the ganglion cell layer. Sanger sequencing of COL18A1, a related multiplexin collagen, identified a rare variant, A1381T, in members of three additional pedigrees with early-onset disease. These results suggest genetic variation in COL15A1 and COL18A1 can modify the age of onset of both early and late onset POAG.


Assuntos
Colágeno Tipo XVIII/genética , Colágeno/genética , Variação Genética , Glaucoma de Ângulo Aberto/genética , Adulto , Idade de Início , Idoso , Animais , Éxons , Feminino , Genótipo , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Linhagem , Polimorfismo de Nucleotídeo Único
14.
Semin Immunol ; 21(6): 328-33, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19775910

RESUMO

Multiple sclerosis (MS) is an idiopathic autoimmune neurodegenerative disease. Like many common diseases, MS has a genetic component; however, as with most complex diseases, the genetic architecture may be influenced by heterogeneity, incomplete penetrance, polygenic inheritance, and environmental factors. This clinically complex disease has provided great challenges for geneticists over the years. Although the first consistent genetic association to MS (with HLA-DR*1501) was discovered more than 30 years ago, lack of consistently replicated genetic results has plagued the scientific community. New study design methods (particularly genome-wide associations studies [GWAS]) along with genome project data and larger datasets have allowed several additional MS genes to be identified and consistently replicated. Thus, after many years of frustration, the strong genetic component associated with MS is finally beginning to be characterized.


Assuntos
Esclerose Múltipla/genética , Animais , Estudo de Associação Genômica Ampla , Humanos , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/epidemiologia
15.
Nat Genet ; 4(2): 160-4, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8102296

RESUMO

Familial dysautonomia (DYS), the Riley-Day syndrome, is an autosomal recessive disorder characterized by developmental loss of neurons from the sensory and autonomic nervous system. It is limited to the Ashkenazi Jewish population, where the carrier frequency is 1 in 30. We have mapped the DYS gene to chromosome 9q31-q33 by linkage with ten DNA markers in 26 families. The maximum lod score of 21.1 with no recombinants was achieved with D9S58. This marker also showed strong linkage disequilibrium with DYS, with one allele present on 73% of affected chromosomes compared to 5.4% of controls (chi 2 = 3142, 15 d.f. p < 0.0001). D9S53 and D9S105 represent the closest flanking markers for the disease gene. This localization will permit prenatal diagnosis of DYS in affected families and aid the isolation of the disease gene.


Assuntos
Cromossomos Humanos Par 9 , Disautonomia Familiar/genética , Marcadores Genéticos , Polimorfismo Genético , Alelos , Mapeamento Cromossômico , Disautonomia Familiar/diagnóstico , Disautonomia Familiar/epidemiologia , Disautonomia Familiar/etnologia , Feminino , Doenças Fetais/diagnóstico , Doenças Fetais/genética , Frequência do Gene , Genes Recessivos , Triagem de Portadores Genéticos , Humanos , Incidência , Judeus/genética , Desequilíbrio de Ligação , Escore Lod , Masculino , Linhagem , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Diagnóstico Pré-Natal
16.
Nat Genet ; 2(1): 37-41, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1303246

RESUMO

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder of unknown aetiology that affects numerous body systems including skin, brain and kidneys. Some TSC has been linked to chromosome 9, additional TSC genes on chromosomes 11 and 12 have been proposed, but the majority of TSC families remain unlinked. Using TSC families in which data had excluded linkage to chromosome 9, we failed to detect linkage with loci on chromosomes 11, 12 and others. One marker examined was D16S283, the closest locus on the proximal side of the polycystic kidney disease type 1 (PKD1) gene. Linkage between TSC and D16S283 demonstrated a lod score of 9.50 at theta = 0.02 with one family independently presenting a lod score of 4.44 at theta = 0.05. These data reveal an important TSC locus near the region of PKD1 on chromosome 16p13.


Assuntos
Cromossomos Humanos Par 16 , Ligação Genética , Rim Policístico Autossômico Dominante/genética , Esclerose Tuberosa/genética , Alelos , Feminino , Genes Dominantes , Marcadores Genéticos , Humanos , Escore Lod , Masculino , Linhagem
17.
Nat Genet ; 10(1): 89-93, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7647799

RESUMO

A heterogeneous group of neurological disorders known as the spinocerebellar ataxias (SCA) are characterized by degeneration of the cerebellum, spinal cord and brainstem. We describe linkage analysis in four unusual SCA families revealing a distinct disease locus on chromosome 3p14-21.1. The disease in these families is distinguished from other forms of SCA by concomitant retinal degeneration. Initial visual problems leading to blindness, disabling ataxia and anticipation are seen in all kindreds. The anticipation in these families suggests a dynamic mutation at this locus. Eventual molecular characterization of this disease may provide valuable insights into the processes of both neural and retinal degeneration.


Assuntos
Cromossomos Humanos Par 3 , Degeneração Retiniana/genética , Degenerações Espinocerebelares/genética , Adolescente , Adulto , Idade de Início , Alelos , População Negra/genética , Criança , Pré-Escolar , Defeitos da Visão Cromática/complicações , Feminino , Ligação Genética , Marcadores Genéticos , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Linhagem , Degeneração Retiniana/complicações , Degeneração Retiniana/diagnóstico , População Branca/genética
18.
Nat Genet ; 7(3): 425-8, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7920663

RESUMO

Amyotrophic lateral sclerosis (ALS) usually presents as a sporadic disorder of motor neurons. However, familial forms of ALS have been described--autosomal dominant forms (ALS1, ALS3), clinically indistinguishable from the sporadic form, and autosomal recessive forms with early onset and slower progression of symptoms (ALS2). To localize the gene for one of the autosomal recessive forms of ALS, we applied linkage analysis to a large inbred family from Tunisia. A lod score maximum of Zmax = 8.2 at theta = 0.00 was obtained with marker D2S72 located on chromosome 2q33-q35. The fine mapping of this region suggested that the ALS2 locus lies in the 8 cM segment flanked by D2S155 and D2S115.


Assuntos
Esclerose Lateral Amiotrófica/genética , Cromossomos Humanos Par 2/genética , Genes Recessivos , Adolescente , Adulto , Esclerose Lateral Amiotrófica/classificação , Criança , Pré-Escolar , Mapeamento Cromossômico , Consanguinidade , Feminino , Marcadores Genéticos , Haplótipos/genética , Humanos , Escore Lod , Masculino , Linhagem , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , Sequências Repetitivas de Ácido Nucleico , Tunísia/epidemiologia
19.
Nat Genet ; 29(1): 23-4, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11528386

RESUMO

A C-->G nucleotide transition in exon 4 of PTPRC (encoding protein-tyrosine phosphatase receptor-type C, also known as CD45) was recently reported to be genetically associated with the development of multiple sclerosis (MS). We performed an extensive evaluation of this polymorphism using large family-based and case-control comparisons. Overall, we observed no evidence of genetic association between the PTPRC polymorphism and MS susceptibility or disease course.


Assuntos
Antígenos Comuns de Leucócito/genética , Esclerose Múltipla/genética , Adulto , Estudos de Casos e Controles , Cromossomos Humanos Par 1 , Éxons , Feminino , Humanos , Masculino , Mutação Puntual , Polimorfismo Genético , Estados Unidos
20.
Nat Genet ; 13(4): 469-71, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8696344

RESUMO

Multiple sclerosis (MS), an inflammatory autoimmune demyelinating disorder of the central nervous system, is the most common cause of acquired neurological dysfunction arising in the second to fourth decades of life. A genetic component to MS is indicated by an increased relative risk of 20-40 to siblings compared to the general population (lambda s), and an increased concordance rate in monozygotic compared to dizygotic twins. Association and/or linkage studies to candidate genes have produced many reports of significant genetic effects including those for the major histocompatability complex (MHC; particularly the HLA-DR2 allele), immunoglobulin heavy chain (IgH), T-cell receptor (TCR) and myelin basic protein (MBP) loci. With the exception of the MHC, however, these results have been difficult to replicate and/or apply beyond isolated populations. We have therefore conducted a two-stage, multi-analytical genomic screen to identify genomic regions potentially harbouring MS susceptibility genes. We genotyped 443 markers and 19 such regions were identified. These included the MHC region on 6p, the only region with a consistently reported genetic effect. However, no single locus generated overwhelming evidence of linkage. Our results suggest that a multifactorial aetiology, including both environmental and multiple genetic factors of moderate effect, is more likely than an aetiology consisting of simple mendelian disease gene(s).


Assuntos
Cromossomos Humanos Par 6 , Complexo Principal de Histocompatibilidade , Esclerose Múltipla/genética , Mapeamento Cromossômico/métodos , Cromossomos Humanos Par 7/genética , Ligação Genética , Marcadores Genéticos , Humanos , Linhagem
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