RESUMO
Enhancing independence and quality of life are key modifiable outcomes that are short- and long-term goals for children with Down syndrome and for their parents. Here we report the outcome of a 4-week feasibility study in a cohort of 26 children with Down Syndrome, 7-17 years old, who used an assistive technology approach that incorporated smart device software and step-by-step pictures (the MapHabit System). Parents reported improvements in children's activities of daily living, quality of life, and independence. They recommended this technology to other families. This report and its findings underscore the feasibility of using assistive technology in children with Down syndrome within home and family settings. A limiting factor is whether participants who did not complete the study, and thus were not included in analyses, might have impacted the study outcomes. The current findings that assistive technology can be used successfully and effectively in family and home settings set the stage for more informative systematic studies using assistive technology for this population. Trial registration: The clinical trial is registered with ClinicalTrials.gov Registration number: NCT05343468.
Assuntos
Síndrome de Down , Tecnologia Assistiva , Humanos , Criança , Adolescente , Qualidade de Vida , Estudos de Viabilidade , Atividades CotidianasRESUMO
With improved healthcare, the Down syndrome (DS) population is both growing and aging rapidly. However, with longevity comes a very high risk of Alzheimer's disease (AD). The LIFE-DSR study (NCT04149197) is a longitudinal natural history study recruiting 270 adults with DS over the age of 25. The study is designed to characterize trajectories of change in DS-associated AD (DS-AD). The current study reports its cross-sectional analysis of the first 90 subjects enrolled. Plasma biomarkers phosphorylated tau protein (p-tau), neurofilament light chain (NfL), amyloid ß peptides (Aß1-40, Aß1-42), and glial fibrillary acidic protein (GFAP) were undertaken with previously published methods. The clinical data from the baseline visit include demographics as well as the cognitive measures under the Severe Impairment Battery (SIB) and Down Syndrome Mental Status Examination (DS-MSE). Biomarker distributions are described with strong statistical associations observed with participant age. The biomarker data contributes to understanding DS-AD across the spectrum of disease. Collectively, the biomarker data show evidence of DS-AD progression beginning at approximately 40 years of age. Exploring these data across the full LIFE-DSR longitudinal study population will be an important resource in understanding the onset, progression, and clinical profiles of DS-AD pathophysiology.
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The Genotype-Tissue Expression (GTEx) project, sponsored by the NIH Common Fund, was established to study the correlation between human genetic variation and tissue-specific gene expression in non-diseased individuals. A significant challenge was the collection of high-quality biospecimens for extensive genomic analyses. Here we describe how a successful infrastructure for biospecimen procurement was developed and implemented by multiple research partners to support the prospective collection, annotation, and distribution of blood, tissues, and cell lines for the GTEx project. Other research projects can follow this model and form beneficial partnerships with rapid autopsy and organ procurement organizations to collect high quality biospecimens and associated clinical data for genomic studies. Biospecimens, clinical and genomic data, and Standard Operating Procedures guiding biospecimen collection for the GTEx project are available to the research community.
Assuntos
Pesquisa Biomédica , Bancos de Tecidos , Obtenção de Tecidos e Órgãos , Pesquisa Biomédica/métodos , Pesquisa Biomédica/organização & administração , Pesquisa Biomédica/normas , Humanos , Obtenção de Tecidos e Órgãos/métodos , Obtenção de Tecidos e Órgãos/organização & administração , Obtenção de Tecidos e Órgãos/normasRESUMO
Age at menopause marks the end of a woman's reproductive life and its timing associates with risks for cancer, cardiovascular and bone disorders. GWAS and candidate gene studies conducted in women of European ancestry have identified 27 loci associated with age at menopause. The relevance of these loci to women of African ancestry has not been previously studied. We therefore sought to uncover additional menopause loci and investigate the relevance of European menopause loci by performing a GWAS meta-analysis in 6510 women with African ancestry derived from 11 studies across the USA. We did not identify any additional loci significantly associated with age at menopause in African Americans. We replicated the associations between six loci and age at menopause (P-value < 0.05): AMHR2, RHBLD2, PRIM1, HK3/UMC1, BRSK1/TMEM150B and MCM8. In addition, associations of 14 loci are directionally consistent with previous reports. We provide evidence that genetic variants influencing reproductive traits identified in European populations are also important in women of African ancestry residing in USA.
Assuntos
Negro ou Afro-Americano/genética , Menopausa/etnologia , Menopausa/genética , População Branca/genética , Fatores Etários , Cromossomos Humanos , Feminino , Loci Gênicos , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Estados UnidosRESUMO
Central obesity, measured by waist circumference (WC) or waist-hip ratio (WHR), is a marker of body fat distribution. Although obesity disproportionately affects minority populations, few studies have conducted genome-wide association study (GWAS) of fat distribution among those of predominantly African ancestry (AA). We performed GWAS of WC and WHR, adjusted and unadjusted for BMI, in up to 33,591 and 27,350 AA individuals, respectively. We identified loci associated with fat distribution in AA individuals using meta-analyses of GWA results for WC and WHR (stage 1). Overall, 25 SNPs with single genomic control (GC)-corrected p-values<5.0 × 10(-6) were followed-up (stage 2) in AA with WC and with WHR. Additionally, we interrogated genomic regions of previously identified European ancestry (EA) WHR loci among AA. In joint analysis of association results including both Stage 1 and 2 cohorts, 2 SNPs demonstrated association, rs2075064 at LHX2, p = 2.24×10(-8) for WC-adjusted-for-BMI, and rs6931262 at RREB1, p = 2.48×10(-8) for WHR-adjusted-for-BMI. However, neither signal was genome-wide significant after double GC-correction (LHX2: p = 6.5 × 10(-8); RREB1: p = 5.7 × 10(-8)). Six of fourteen previously reported loci for waist in EA populations were significant (p<0.05 divided by the number of independent SNPs within the region) in AA studied here (TBX15-WARS2, GRB14, ADAMTS9, LY86, RSPO3, ITPR2-SSPN). Further, we observed associations with metabolic traits: rs13389219 at GRB14 associated with HDL-cholesterol, triglycerides, and fasting insulin, and rs13060013 at ADAMTS9 with HDL-cholesterol and fasting insulin. Finally, we observed nominal evidence for sexual dimorphism, with stronger results in AA women at the GRB14 locus (p for interaction = 0.02). In conclusion, we identified two suggestive loci associated with fat distribution in AA populations in addition to confirming 6 loci previously identified in populations of EA. These findings reinforce the concept that there are fat distribution loci that are independent of generalized adiposity.
Assuntos
População Negra/genética , Distribuição da Gordura Corporal , Estudo de Associação Genômica Ampla , Obesidade/genética , Adiposidade/genética , Feminino , Loci Gênicos , Humanos , Masculino , Obesidade/patologia , Polimorfismo de Nucleotídeo Único , Relação Cintura-Quadril , População Branca/genéticaRESUMO
Genome-wide association studies (GWAS) have identified 36 loci associated with body mass index (BMI), predominantly in populations of European ancestry. We conducted a meta-analysis to examine the association of >3.2 million SNPs with BMI in 39,144 men and women of African ancestry and followed up the most significant associations in an additional 32,268 individuals of African ancestry. We identified one new locus at 5q33 (GALNT10, rs7708584, P = 3.4 × 10(-11)) and another at 7p15 when we included data from the GIANT consortium (MIR148A-NFE2L3, rs10261878, P = 1.2 × 10(-10)). We also found suggestive evidence of an association at a third locus at 6q16 in the African-ancestry sample (KLHL32, rs974417, P = 6.9 × 10(-8)). Thirty-two of the 36 previously established BMI variants showed directionally consistent effect estimates in our GWAS (binomial P = 9.7 × 10(-7)), five of which reached genome-wide significance. These findings provide strong support for shared BMI loci across populations, as well as for the utility of studying ancestrally diverse populations.
Assuntos
Negro ou Afro-Americano/genética , Índice de Massa Corporal , Obesidade/genética , Estudos de Casos e Controles , Frequência do Gene , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Desequilíbrio de Ligação , Obesidade/etnologia , Polimorfismo de Nucleotídeo ÚnicoRESUMO
African-American (AA) women have earlier menarche on average than women of European ancestry (EA), and earlier menarche is a risk factor for obesity and type 2 diabetes among other chronic diseases. Identification of common genetic variants associated with age at menarche has a potential value in pointing to the genetic pathways underlying chronic disease risk, yet comprehensive genome-wide studies of age at menarche are lacking for AA women. In this study, we tested the genome-wide association of self-reported age at menarche with common single-nucleotide polymorphisms (SNPs) in a total of 18 089 AA women in 15 studies using an additive genetic linear regression model, adjusting for year of birth and population stratification, followed by inverse-variance weighted meta-analysis (Stage 1). Top meta-analysis results were then tested in an independent sample of 2850 women (Stage 2). First, while no SNP passed the pre-specified P < 5 × 10(-8) threshold for significance in Stage 1, suggestive associations were found for variants near FLRT2 and PIK3R1, and conditional analysis identified two independent SNPs (rs339978 and rs980000) in or near RORA, strengthening the support for this suggestive locus identified in EA women. Secondly, an investigation of SNPs in 42 previously identified menarche loci in EA women demonstrated that 25 (60%) of them contained variants significantly associated with menarche in AA women. The findings provide the first evidence of cross-ethnic generalization of menarche loci identified to date, and suggest a number of novel biological links to menarche timing in AA women.
Assuntos
Negro ou Afro-Americano/genética , Estudo de Associação Genômica Ampla , Menarca/genética , Adolescente , Estudos de Casos e Controles , Criança , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Feminino , Loci Gênicos , Variação Genética , Humanos , Modelos Lineares , Glicoproteínas de Membrana , Proteínas de Membrana/genética , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Obesidade/genética , Polimorfismo de Nucleotídeo Único , Fatores de Risco , População Branca/genética , Adulto JovemRESUMO
Adult height is a classic polygenic trait of high heritability (h(2) approximately 0.8). More than 180 single nucleotide polymorphisms (SNPs), identified mostly in populations of European descent, are associated with height. These variants convey modest effects and explain approximately10% of the variance in height. Discovery efforts in other populations, while limited, have revealed loci for height not previously implicated in individuals of European ancestry. Here, we performed a meta-analysis of genome-wide association (GWA) results for adult height in 20,427 individuals of African ancestry with replication in up to 16,436 African Americans. We found two novel height loci (Xp22-rs12393627, Pâ=â3.4×10(-12) and 2p14-rs4315565, Pâ=â1.2×10(-8)). As a group, height associations discovered in European-ancestry samples replicate in individuals of African ancestry (Pâ=â1.7×10(-4) for overall replication). Fine-mapping of the European height loci in African-ancestry individuals showed an enrichment of SNPs that are associated with expression of nearby genes when compared to the index European height SNPs (P<0.01). Our results highlight the utility of genetic studies in non-European populations to understand the etiology of complex human diseases and traits.
Assuntos
Negro ou Afro-Americano/genética , Estatura/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Mapeamento Cromossômico , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único , População Branca/genéticaRESUMO
Total white blood cell (WBC) and neutrophil counts are lower among individuals of African descent due to the common African-derived "null" variant of the Duffy Antigen Receptor for Chemokines (DARC) gene. Additional common genetic polymorphisms were recently associated with total WBC and WBC sub-type levels in European and Japanese populations. No additional loci that account for WBC variability have been identified in African Americans. In order to address this, we performed a large genome-wide association study (GWAS) of total WBC and cell subtype counts in 16,388 African-American participants from 7 population-based cohorts available in the Continental Origins and Genetic Epidemiology Network. In addition to the DARC locus on chromosome 1q23, we identified two other regions (chromosomes 4q13 and 16q22) associated with WBC in African Americans (P<2.5×10(-8)). The lead SNP (rs9131) on chromosome 4q13 is located in the CXCL2 gene, which encodes a chemotactic cytokine for polymorphonuclear leukocytes. Independent evidence of the novel CXCL2 association with WBC was present in 3,551 Hispanic Americans, 14,767 Japanese, and 19,509 European Americans. The index SNP (rs12149261) on chromosome 16q22 associated with WBC count is located in a large inter-chromosomal segmental duplication encompassing part of the hydrocephalus inducing homolog (HYDIN) gene. We demonstrate that the chromosome 16q22 association finding is most likely due to a genotyping artifact as a consequence of sequence similarity between duplicated regions on chromosomes 16q22 and 1q21. Among the WBC loci recently identified in European or Japanese populations, replication was observed in our African-American meta-analysis for rs445 of CDK6 on chromosome 7q21 and rs4065321 of PSMD3-CSF3 region on chromosome 17q21. In summary, the CXCL2, CDK6, and PSMD3-CSF3 regions are associated with WBC count in African American and other populations. We also demonstrate that large inter-chromosomal duplications can result in false positive associations in GWAS.
Assuntos
Negro ou Afro-Americano/genética , Estudo de Associação Genômica Ampla , Contagem de Leucócitos , Epidemiologia Molecular , Artefatos , Povo Asiático/genética , Quimiocina CXCL2/genética , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 16/genética , Cromossomos Humanos Par 4/genética , Replicação do DNA/genética , Sistema do Grupo Sanguíneo Duffy/genética , Loci Gênicos/genética , Humanos , Proteínas dos Microfilamentos/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Receptores de Superfície Celular/genética , Reprodutibilidade dos Testes , População Branca/genéticaRESUMO
BACKGROUND AND PURPOSE: Ischemic stroke (IS) is a multifactorial disorder with strong evidence from twin, family, and animal model studies suggesting a genetic influence on risk and prognosis. Several candidate genes for IS have been proposed, but few have been replicated. We investigated the contribution of 67 candidate genes (369 single nucleotide polymorphisms [SNPs]) on the risk of IS in a North American population of European descent. METHODS: Two independent studies were performed. In the first, 342 SNPs from 52 candidate genes were genotyped in 307 IS cases and 324 control subjects. The SNPs significantly associated with IS were tested for replication in another cohort of 583 IS cases and 270 control subjects. In the second study, 212 SNPs from 62 candidate genes were analyzed in 710 IS cases with subtyping available and 3751 control subjects. RESULTS: None of the candidate genes (SNPs) were significantly associated with IS risk independent of known stroke risk factors after correction for multiple hypotheses testing. CONCLUSIONS: These results are consistent with previous meta-analyses that demonstrate an absence of genetic association of variants in plausible candidate genes with IS risk. Our study suggests that the effect of the investigated SNPs may be weak or restricted to specific populations or IS subtypes.
Assuntos
Isquemia Encefálica/genética , Polimorfismo de Nucleotídeo Único/genética , Acidente Vascular Cerebral/genética , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/epidemiologia , Estudos de Casos e Controles , Feminino , Marcadores Genéticos/genética , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/epidemiologiaRESUMO
The cause of sporadic amyotrophic lateral sclerosis (ALS) is largely unknown, but genetic factors are thought to play a significant role in determining susceptibility to motor neuron degeneration. To identify genetic variants altering risk of ALS, we undertook a two-stage genome-wide association study (GWAS): we followed our initial GWAS of 545 066 SNPs in 553 individuals with ALS and 2338 controls by testing the 7600 most associated SNPs from the first stage in three independent cohorts consisting of 2160 cases and 3008 controls. None of the SNPs selected for replication exceeded the Bonferroni threshold for significance. The two most significantly associated SNPs, rs2708909 and rs2708851 [odds ratio (OR) = 1.17 and 1.18, and P-values = 6.98 x 10(-7) and 1.16 x 10(-6)], were located on chromosome 7p13.3 within a 175 kb linkage disequilibrium block containing the SUNC1, HUS1 and C7orf57 genes. These associations did not achieve genome-wide significance in the original cohort and failed to replicate in an additional independent cohort of 989 US cases and 327 controls (OR = 1.18 and 1.19, P-values = 0.08 and 0.06, respectively). Thus, we chose to cautiously interpret our data as hypothesis-generating requiring additional confirmation, especially as all previously reported loci for ALS have failed to replicate successfully. Indeed, the three loci (FGGY, ITPR2 and DPP6) identified in previous GWAS of sporadic ALS were not significantly associated with disease in our study. Our findings suggest that ALS is more genetically and clinically heterogeneous than previously recognized. Genotype data from our study have been made available online to facilitate such future endeavors.
Assuntos
Esclerose Lateral Amiotrófica/genética , Estudos de Casos e Controles , Genoma Humano , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Several genetic variations have been associated with Parkinson disease in different populations over the past few years. Although a considerable number of worldwide populations have been screened for these variants, results from Sub-Saharan populations are very scarce in the literature. In the present report we have screened a cohort of Parkinson disease patients (n = 57) and healthy controls (n = 51) from Nigeria for mutations in the genes PRKN, LRRK2 and ATXN3. No pathogenic mutations were found in any of the genes. Hence, common pathogenic mutations in these genes, observed in several different populations, are not a frequent cause of Parkinson disease in Nigeria.
Assuntos
Mutação , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Doença de Parkinson/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Repressoras/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Idoso , Ataxina-3 , Estudos de Casos e Controles , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Masculino , Pessoa de Meia-Idade , Nigéria , Doença de Parkinson/epidemiologiaRESUMO
There is considerable evidence that human genetic variation influences gene expression. Genome-wide studies have revealed that mRNA levels are associated with genetic variation in or close to the gene coding for those mRNA transcripts - cis effects, and elsewhere in the genome - trans effects. The role of genetic variation in determining protein levels has not been systematically assessed. Using a genome-wide association approach we show that common genetic variation influences levels of clinically relevant proteins in human serum and plasma. We evaluated the role of 496,032 polymorphisms on levels of 42 proteins measured in 1200 fasting individuals from the population based InCHIANTI study. Proteins included insulin, several interleukins, adipokines, chemokines, and liver function markers that are implicated in many common diseases including metabolic, inflammatory, and infectious conditions. We identified eight Cis effects, including variants in or near the IL6R (p = 1.8x10(-57)), CCL4L1 (p = 3.9x10(-21)), IL18 (p = 6.8x10(-13)), LPA (p = 4.4x10(-10)), GGT1 (p = 1.5x10(-7)), SHBG (p = 3.1x10(-7)), CRP (p = 6.4x10(-6)) and IL1RN (p = 7.3x10(-6)) genes, all associated with their respective protein products with effect sizes ranging from 0.19 to 0.69 standard deviations per allele. Mechanisms implicated include altered rates of cleavage of bound to unbound soluble receptor (IL6R), altered secretion rates of different sized proteins (LPA), variation in gene copy number (CCL4L1) and altered transcription (GGT1). We identified one novel trans effect that was an association between ABO blood group and tumour necrosis factor alpha (TNF-alpha) levels (p = 6.8x10(-40)), but this finding was not present when TNF-alpha was measured using a different assay , or in a second study, suggesting an assay-specific association. Our results show that protein levels share some of the features of the genetics of gene expression. These include the presence of strong genetic effects in cis locations. The identification of protein quantitative trait loci (pQTLs) may be a powerful complementary method of improving our understanding of disease pathways.
Assuntos
Proteínas Sanguíneas/genética , Genoma Humano , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas Sanguíneas/metabolismo , Feminino , Dosagem de Genes , Ligação Genética , Variação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Transcrição GênicaRESUMO
Genome-wide patterns of variation across individuals provide a powerful source of data for uncovering the history of migration, range expansion, and adaptation of the human species. However, high-resolution surveys of variation in genotype, haplotype and copy number have generally focused on a small number of population groups. Here we report the analysis of high-quality genotypes at 525,910 single-nucleotide polymorphisms (SNPs) and 396 copy-number-variable loci in a worldwide sample of 29 populations. Analysis of SNP genotypes yields strongly supported fine-scale inferences about population structure. Increasing linkage disequilibrium is observed with increasing geographic distance from Africa, as expected under a serial founder effect for the out-of-Africa spread of human populations. New approaches for haplotype analysis produce inferences about population structure that complement results based on unphased SNPs. Despite a difference from SNPs in the frequency spectrum of the copy-number variants (CNVs) detected--including a comparatively large number of CNVs in previously unexamined populations from Oceania and the Americas--the global distribution of CNVs largely accords with population structure analyses for SNP data sets of similar size. Our results produce new inferences about inter-population variation, support the utility of CNVs in human population-genetic research, and serve as a genomic resource for human-genetic studies in diverse worldwide populations.
Assuntos
Dosagem de Genes/genética , Variação Genética/genética , Genoma Humano/genética , Geografia , Haplótipos/genética , África , Alelos , Cromossomos Humanos Par 2/genética , Genética Populacional , Humanos , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Technological advances in molecular genetics allow rapid and sensitive identification of genomic copy number variants (CNVs). This, in turn, has sparked interest in the function such variation may play in disease. While a role for copy number mutations as a cause of Mendelian disorders is well established, it is unclear whether CNVs may affect risk for common complex disorders. We sought to investigate whether CNVs may modulate risk for ischemic stroke (IS) and to provide a catalog of CNVs in patients with this disorder by analyzing copy number metrics produced as a part of our previous genome-wide single-nucleotide polymorphism (SNP)-based association study of ischemic stroke in a North American white population. We examined CNVs in 263 patients with ischemic stroke (IS). Each identified CNV was compared with changes identified in 275 neurologically normal controls. Our analysis identified 247 CNVs, corresponding to 187 insertions (76%; 135 heterozygous; 25 homozygous duplications or triplications; 2 heterosomic) and 60 deletions (24%; 40 heterozygous deletions; 3 homozygous deletions; 14 heterosomic deletions). Most alterations (81%) were the same as, or overlapped with, previously reported CNVs. We report here the first genome-wide analysis of CNVs in IS patients. In summary, our study did not detect any common genomic structural variation unequivocally linked to IS, although we cannot exclude that smaller CNVs or CNVs in genomic regions poorly covered by this methodology may confer risk for IS. The application of genome-wide SNP arrays now facilitates the evaluation of structural changes through the entire genome as part of a genome-wide genetic association study.
Assuntos
Isquemia Encefálica/genética , Dosagem de Genes , Acidente Vascular Cerebral/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Genoma Humano , Humanos , Masculino , Pessoa de Meia-Idade , América do Norte , Polimorfismo de Nucleotídeo Único , Fatores de Risco , População Branca/genéticaRESUMO
Technologies that allow genotyping of more than 100,000 polymorphisms in a single assay enable the execution of genomewide SNP (GWSNP) association studies to identify common genetic variants underlying traits. Less appreciated is the ability of GWSNP assays to map and directly identify rare mutations that cause disease. Here we show the use of this approach in identifying rare structural mutations involved in disease using a large cohort of Parkinson disease (PD) patients and neurologically normal controls by examination of genotype data and copy number metrics. This approach revealed a patient with homozygous mutation at the PARK2 locus. In addition, two heterozygous deletion mutations and five heterozygous duplication mutations within PARK2 were identified in PD subjects and controls. All mutations were confirmed by independent gene dosage experiments. These data demonstrate the utility of this approach in the direct detection of mutations that underlie disease.
Assuntos
Genoma Humano/genética , Mutação/genética , Doença de Parkinson/genética , Polimorfismo de Nucleotídeo Único/genética , Idoso , Idoso de 80 Anos ou mais , Éxons , Feminino , Deleção de Genes , Dosagem de Genes , Duplicação Gênica , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND: Recently, mutations in LRRK2 encoding the protein dardarin have been linked to an autosomal dominant form of parkinsonism. OBJECTIVE: To identify mutations causing Parkinson's disease (PD) in a cohort of North Americans with familial PD. METHODS: We sequenced exons 1-51 of LRRK2 in 79 unrelated North American PD patients reporting a family history of the disease. RESULTS: One patient had a missense mutation (Thr2356Ile) while two others had the common Gly2019Ser mutation. In addition, 1 patient had a 4-bp deletion in close proximity to the exon 19 splice donor (IVS20+4delGTAA) that in vitro abrogates normal splicing. CONCLUSIONS: Our observations in the 79 North American patients indicate that mutations in LRRK2 are associated with approximately 5% of PD cases with a positive family history. The results also show that G2019S represents approximately half of the LRRK2 mutations in United States PD cases with a family history of the disease. We have identified two novel mutations in LRRK2.
Assuntos
Química Encefálica/genética , Predisposição Genética para Doença/genética , Mutação/genética , Doença de Parkinson/genética , Proteínas Serina-Treonina Quinases/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Processamento Alternativo/genética , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Sequência de Bases , Estudos de Coortes , Análise Mutacional de DNA , Marcadores Genéticos/genética , Testes Genéticos , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação de Sentido Incorreto/genética , América do Norte , Doença de Parkinson/metabolismo , Doença de Parkinson/fisiopatologia , Sítios de Splice de RNA/genéticaRESUMO
BACKGROUND: Despite evidence of a genetic role in stroke, the identification of common genetic risk factors for this devastating disorder remains problematic. We aimed to identify any common genetic variability exerting a moderate to large effect on risk of ischaemic stroke, and to generate publicly available genome-wide genotype data to facilitate others doing the same. METHODS: We applied a genome-wide high-density single-nucleotide-polymorphism (SNP) genotyping approach to a cohort of samples with and without ischaemic stroke (n=278 and 275, respectively), and did an association analysis adjusted for known confounders in a final cohort of 249 cases and 268 controls. More than 400,000 unique SNPs were assayed. FINDINGS: We produced more than 200 million genotypes in 553 unique participants. The raw genotypes of all the controls have been posted publicly in a previous study of Parkinson's disease. From this effort, results of genotype and allele association tests have been publicly posted for 88% of stroke patients who provided proper consent for public release. Preliminary analysis of these data did not reveal any single locus conferring a large effect on risk for ischaemic stroke. INTERPRETATION: The data generated here comprise the first phase of a genome-wide association analysis in patients with stroke. Release of phase I results generated in these publicly available samples from each consenting individual makes this dataset a valuable resource for data-mining and augmentation.
Assuntos
Isquemia Encefálica/complicações , Predisposição Genética para Doença , Genoma Humano , Acidente Vascular Cerebral/etiologia , Idoso , Alelos , Estudos de Coortes , Feminino , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Acidente Vascular Cerebral/genéticaRESUMO
BACKGROUND: The cause of sporadic ALS is currently unknown. Despite evidence for a role for genetics, no common genetic variants have been unequivocally linked to sporadic ALS. We sought to identify genetic variants associated with an increased or decreased risk for developing ALS in a cohort of American sporadic cases. METHODS: We undertook a genome-wide association study using publicly available samples from 276 patients with sporadic ALS and 271 neurologically normal controls. 555 352 unique SNPs were assayed in each sample using the Illumina Infinium II HumanHap550 SNP chip. FINDINGS: More than 300 million genotypes were produced in 547 participants. These raw genotype data are freely available on the internet and represent the first publicly accessible SNP data for ALS cases. 34 SNPs with a p value less than 0.0001 (two degrees of freedom) were found, although none of these reached significance after Bonferroni correction. INTERPRETATION: We generated publicly available genotype data for sporadic ALS patients and controls. No single locus was definitively associated with increased risk of developing disease, although potentially associated candidate SNPs were identified.
Assuntos
Esclerose Lateral Amiotrófica/genética , Análise Mutacional de DNA/métodos , Testes Genéticos/métodos , Genótipo , Biologia Molecular/métodos , Setor Público/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Bases de Dados Genéticas/normas , Bases de Dados Genéticas/tendências , Feminino , Marcadores Genéticos/genética , Predisposição Genética para Doença/genética , Biblioteca Genômica , Humanos , Masculino , Pessoa de Meia-Idade , Biologia Molecular/tendências , Mutação/genética , Polimorfismo de Nucleotídeo Único/genética , Valores de ReferênciaRESUMO
RATIONALE: Individuals vary in their susceptibility to nicotine addiction. However, there is little evidence that behavioral sensitivity to nicotine is dependent upon the functional state of nicotinic cholinergic receptors (nAChRs). OBJECTIVE: This study aims to determine the relationship between in vivo behavioral desensitization and in vitro desensitization of nAChR function. METHODS: Male Sprague-Dawley rats trained to discriminate nicotine were tested for development of acute behavioral tolerance. The rats were injected with nicotine (0.4 mg/kg free base, s.c.), tested for nicotine discrimination for 2 min, then injected with the same dose of nicotine 90, 180, and 270 min after the first injection and tested for nicotine discrimination after each injection. Susceptibility of nAChRs of individual rats to desensitization was assessed by use of the (86)Rb(+) efflux assay using synaptosomes prepared from the "thalamus," which included the hypothalamus and midbrain as well as the thalamic nuclei. To desensitize nAChRs, synaptsosomes were superfused with low concentrations of nicotine (5, 10, 20, and 30 nM) before stimulation of (86)Rb(+) efflux with nicotine (10 muM). RESULTS: The slopes of the behavioral desensitization were plotted as a function of the decline of nicotine-stimulated (86)Rb(+) efflux after in vitro desensitization. A significant correlation was observed between the in vitro desensitization of thalamic (86)Rb(+) efflux and the extent of behavioral desensitization of individual rats. CONCLUSIONS: These findings are consistent with the idea that production of acute behavioral tolerance by nicotine is related to its ability to induce nAChR desensitization at the cellular level.