RESUMO
OBJECTIVES: Dysfunction of the hypothalamus-pituitary-adrenal (HPA) axis is one of the most consistent findings in the pathophysiology of mood disorders. The potential role of genes related to HPA axis function has been investigated extensively in major depression. However, in bipolar disorder (BPD) such studies are scarce. We performed a systematic HapMap-based association study of six genes crucial for HPA axis function in relation to BPD. METHODS: Haplotype tagging single nucleotide polymorphisms (htSNPs) were selected in order to identify all haplotypes with a frequency of more than 1% in the genes encoding the glucocorticoid receptor (GR), mineralocorticoid receptor (MR), corticotrophin releasing hormone receptor 1 (CRH-R1) and 2 (CRH-R2), CRH binding protein (CRH-BP), and FK binding protein 5 (FKBP5). This resulted in a total selection of 225 SNPs that were genotyped and analyzed in 309 BPD patients and 364 matched control individuals all originating from an isolated northern Swedish population. RESULTS: Consistent evidence for an association with BPD was found for NR3C1, the gene encoding GR. Almost all SNPs in two adjacent haplotype blocks contributed to the positive signal, comprised of significant single marker, sliding window, and haplotype-specific p-values. All these results point to a moderately frequent (10-15%) susceptibility haplotype covering the entire coding region and 3' untranslated region (UTR) of NR3C1. CONCLUSIONS: This study contributes to the growing evidence for a role of the glucocorticoid receptor gene (NR3C1) in vulnerability to mood disorders, and BPD in particular, and warrants further in vitro investigation of the at-risk haplotypes with respect to disease etiology. However, this association might be restricted to this specific population, as it is observed in a rather small sample from an isolated population without replication, and data from large meta-analyses for genome-wide association studies in BPD do not show the GR as a very strong candidate.
Assuntos
Transtorno Bipolar/genética , Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único/genética , Receptores de Glucocorticoides/genética , Adulto , Transtorno Bipolar/epidemiologia , Proteínas de Transporte/genética , Estudos de Casos e Controles , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Desequilíbrio de Ligação , Masculino , Receptores de Hormônio Liberador da Corticotropina/genética , Receptores de Mineralocorticoides/genética , Suécia/epidemiologia , Proteínas de Ligação a Tacrolimo/genéticaRESUMO
BACKGROUND: Cancer genomes display characteristic patterns of chromosomal imbalances, often with diagnostic and prognostic relevance. Therefore assays for genome-wide copy number screening and simultaneous detection of copy number alterations in specific chromosomal regions are of increasing importance in the diagnostic work-up of tumors. RESULTS: We tested the performance of Multiplex Amplicon Quantification, a newly developed low-cost, closed-tube and high-throughput PCR-based technique for detection of copy number alterations in regions with prognostic relevance for neuroblastoma. Comparison with array CGH and the established Multiplex Ligation-dependent Probe Amplification method on 52 neuroblastoma tumors showed that Multiplex Amplicon Quantification can reliably detect the important genomic aberrations. CONCLUSION: Multiplex Amplicon Quantification is a low-cost and high-throughput PCR-based technique that can reliably detect copy number alterations in regions with prognostic relevance for neuroblastoma.
Assuntos
Neuroblastoma/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Variações do Número de Cópias de DNA , Humanos , Técnicas de Amplificação de Ácido Nucleico/economia , Reação em Cadeia da PolimeraseRESUMO
Through active reuptake of serotonin into presynaptic neurons, the serotonin transporter (5-HTT) plays an important role in regulating serotonin concentrations in the brain, and it is the site of binding for tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs). Therefore it has been hypothesized that this transporter is involved in the etiology of bipolar (BP) disorder. Inconsistent association study results for the SLC6A4 gene encoding 5-HTT reported in literature emphasize the need for more systematic and detailed analyses of this candidate gene. We performed an extensive analysis of SLC6A4 on DNA of 254 BPI patients and 364 control individuals from a Northern Swedish isolated population. This analysis consisted of a HapMap LD-based association study including three widely investigated polymorphisms (5-HTTVNTR, 5-HTTLPR, and rs3813034), a copy-number variation (CNV) analysis and a mutation analysis of the complete coding sequence and the 3'-UTR of SLC6A4. No single marker showed statistically significant association with BPI, nor did any of the haplotypes. In the mutation analysis 13 novel variants were detected, including 2 amino acid substitutions M389V and I587L, but these are probably not implicated in risk for BP. No deletions or duplications were detected in the CNV analysis. We conclude that variation in the SLC6A4 gene or its regulatory regions does not contribute to the susceptibility for BP disorder in the Northern Swedish population.
Assuntos
Transtorno Bipolar/genética , Frequência do Gene/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Alelos , Transtorno Bipolar/epidemiologia , Éxons/genética , Predisposição Genética para Doença , Genótipo , Haplótipos/genética , Humanos , Íntrons/genética , Mutação/genética , Polimorfismo de Nucleotídeo Único/genética , Suécia/epidemiologiaRESUMO
PURPOSE: To infer the prognostic value of simultaneous androgen receptor (AR) and TP53 profiling in liquid biopsies from patients with metastatic castration-resistant prostate cancer (mCRPC) starting a new line of AR signaling inhibitors (ARSi).Experimental Design: Between March 2014 and April 2017, we recruited patients with mCRPC (n = 168) prior to ARSi in a cohort study encompassing 10 European centers. Blood samples were collected for comprehensive profiling of CellSearch-enriched circulating tumor cells (CTC) and circulating tumor DNA (ctDNA). Targeted CTC RNA sequencing (RNA-seq) allowed the detection of eight AR splice variants (ARV). Low-pass whole-genome and targeted gene-body sequencing of AR and TP53 was applied to identify amplifications, loss of heterozygosity, mutations, and structural rearrangements in ctDNA. Clinical or radiologic progression-free survival (PFS) was estimated by Kaplan-Meier analysis, and independent associations were determined using multivariable Cox regression models. RESULTS: Overall, no single AR perturbation remained associated with adverse prognosis after multivariable analysis. Instead, tumor burden estimates (CTC counts, ctDNA fraction, and visceral metastases) were significantly associated with PFS. TP53 inactivation harbored independent prognostic value [HR 1.88; 95% confidence interval (CI), 1.18-3.00; P = 0.008], and outperformed ARV expression and detection of genomic AR alterations. Using Cox coefficient analysis of clinical parameters and TP53 status, we identified three prognostic groups with differing PFS estimates (median, 14.7 vs. 7.51 vs. 2.62 months; P < 0.0001), which was validated in an independent mCRPC cohort (n = 202) starting first-line ARSi (median, 14.3 vs. 6.39 vs. 2.23 months; P < 0.0001). CONCLUSIONS: In an all-comer cohort, tumor burden estimates and TP53 outperform any AR perturbation to infer prognosis.See related commentary by Rebello et al., p. 1699.
Assuntos
Antagonistas de Receptores de Andrógenos/farmacologia , Antineoplásicos/farmacologia , Biomarcadores Tumorais/sangue , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Proteína Supressora de Tumor p53/sangue , Idoso , Idoso de 80 Anos ou mais , Antagonistas de Receptores de Andrógenos/uso terapêutico , Androstenos/farmacologia , Androstenos/uso terapêutico , Antineoplásicos/uso terapêutico , Benzamidas , DNA Tumoral Circulante/sangue , Intervalo Livre de Doença , Resistencia a Medicamentos Antineoplásicos , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Biópsia Líquida/métodos , Masculino , Células Neoplásicas Circulantes/patologia , Nitrilas , Feniltioidantoína/análogos & derivados , Feniltioidantoína/farmacologia , Feniltioidantoína/uso terapêutico , Valor Preditivo dos Testes , Prognóstico , Intervalo Livre de Progressão , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/mortalidade , RNA-Seq , Receptores Androgênicos/sangue , Receptores Androgênicos/metabolismoRESUMO
The possibility that gene copy number variations play a role in the development of complex disorders is a topic of considerable interest. Recent reports have highlighted the large number of such variations that exist and that their occurrence varies considerably between populations. A recent report has suggested that copy number variations in four genes (GRIK3, EFNA5, AKAP5 and CACNG2) may be associated with schizophrenia. One problem with this area of study is the validation of high throughput methods such as comparative genomic hybridisation, as the latter inevitably generates false positives. We have used two contrasting methodologies to determine the validity of the findings reported above which if true would have major implications for the pathogenesis of schizophrenia. Samples from a UK population were tested using a method of allele quantification by DNA pooling and samples from Belgium and northern Sweden were tested using Multiplex Amplicon Quantification (MAQ). Both methods were used to test DNA samples used in the original investigation. No copy number variations were found for any of the genes in any samples. Our data suggests that more reliable methods need to be used to validate the existence of CNVs before full scale association studies are carried out.
Assuntos
Dosagem de Genes , Variação Genética , Esquizofrenia/genética , Proteínas de Ancoragem à Quinase A/genética , Canais de Cálcio/genética , DNA/genética , Efrinas/genética , Amplificação de Genes , Humanos , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo Único , Receptores de Ácido Caínico/genéticaRESUMO
CONTEXT: Tryptophan hydroxylase is the rate-limiting enzyme in the serotonin (5-HT) biosynthetic pathway responsible for the regulation of serotonin levels. Tryptophan hydroxylase 2 (TPH2) was found to be solely expressed in the brain and therefore considered an important susceptibility gene in psychiatric disorders. OBJECTIVE: To determine the role of the brain-specific TPH2 gene in unipolar (UP) disorder and bipolar (BP) disorder in a northern Swedish, isolated population. DESIGN: HapMap-based haplotype-tagging single nucleotide polymorphism (htSNP) patient-control association study. SETTING: A northern Swedish, isolated population. PARTICIPANTS: One hundred thirty-five unrelated patients with UP disorder, 182 unrelated patients with BP disorder, and 364 unrelated control individuals. RESULTS: Significant allelic association was identified in our UP disorder association sample for an htSNP located in the 5' promoter region (rs11178997; P = .001). Haplotype analysis supported this significant result by the presence of a protective factor on hapblock 2 (P(specific) = .002). In the BP disorder association sample, single-marker association identified a significant htSNP in the upstream regulatory region (rs4131348; P = .004). Moreover, haplotype analysis in the BP disorder sample showed that the same htSNPs from hapblock 2 associated with UP disorder were also significantly associated with BP disorder (P(specific) = .002). CONCLUSIONS: Haplotype-based analysis of TPH2 in patients with UP and BP disorder and controls from northern Swedish descent provides preliminary evidence for protective association in both disorders and thus supports a central role for TPH2 in the pathogenesis of affective disorders.
Assuntos
Transtorno Bipolar/enzimologia , Transtorno Bipolar/genética , Transtorno Depressivo/enzimologia , Transtorno Depressivo/genética , Triptofano Hidroxilase/genética , População Branca/genética , Idoso , Transtorno Bipolar/etnologia , Cromossomos Humanos Par 12/genética , Transtorno Depressivo/etnologia , Feminino , Seguimentos , Expressão Gênica , Marcadores Genéticos , Predisposição Genética para Doença , Genótipo , Haplótipos/genética , Humanos , Desequilíbrio de Ligação/genética , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Serotonina/biossíntese , Serotonina/genética , Suécia/etnologiaRESUMO
Most genetic association studies in bipolar disorder have focussed on genes involved in major neurotransmitter systems or brain development. Functional polymorphisms in the serotonin transporter (5-HTTLPR), catechol-O-methyltransferase (Val158Met) and dopamine D3 receptor (Ser9Gly) genes have all been associated with bipolar disorder. We aimed at investigating whether these functional variants contribute to the genetic etiology of bipolar disorder in a northern Swedish isolated population. Moreover, we wanted to gain information about the synergistic contribution of these functional variants. Neither of these functional polymorphisms was associated with bipolar disorder in the northern Swedish patient-control sample nor did we find evidence of gene-gene interaction. Together, our data suggest that these functional variants are not involved in the etiology of bipolar disorder in the northern Swedish population nor did gene-gene interaction analysis support a central role of these variants in bipolar disorder.
Assuntos
Alelos , Transtorno Bipolar/genética , Polimorfismo de Nucleotídeo Único , Adulto , Catecol O-Metiltransferase/genética , Feminino , Humanos , Masculino , Receptores de Dopamina D3/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , SuéciaRESUMO
Robust statistical, genetic and functional evidence supports a role for DISC1 in the aetiology of major mental illness. Furthermore, many of its protein-binding partners show evidence for involvement in the pathophysiology of a range of neurodevelopmental and psychiatric disorders. Copy number variants (CNVs) are suspected to play an important causal role in these disorders. In this study, CNV analysis of DISC1 and its binding partners PAFAH1B1, NDE1, NDEL1, FEZ1, MAP1A, CIT and PDE4B in Scottish and Northern Swedish population-based samples was carried out using multiplex amplicon quantification. Here, we report the finding of rare CNVs in DISC1, NDE1 (together with adjacent genes within the 16p13.11 duplication), NDEL1 (including the overlapping MYH10 gene) and CIT. Our findings provide further evidence for involvement of DISC1 and its interaction partners in neuropsychiatric disorders and also for a role of structural variants in the aetiology of these devastating diseases.
RESUMO
CONTEXT: Neuregulin 1 (NRG1), a growth factor involved in neurodevelopment, myelination, neurotransmitter receptor expression, and synaptic plasticity, first joined the list of candidate genes for schizophrenia when a 7-marker haplotype at the 5' end of the gene (Hap(ICE)) was shown to be associated with the disorder in the Icelandic population. Since then, more genetic and functional evidence has emerged, which supports a role for NRG1 in the development of schizophrenia. OBJECTIVE: To determine the contribution of NRG1 to susceptibility for schizophrenia in a northern Swedish isolated population. DESIGN: Detailed linkage disequilibrium (LD)-based patient-control association study. This is the first study to type and analyze the 7 Hap(ICE) markers and a set of 32 HapMap tagging single-nucleotide polymorphisms (SNPs) that represents variants with a minor allele frequency of at least 1% and fully characterizes the LD structure of the 5' part of NRG1. SETTING: Outpatient and inpatient hospitals. PARTICIPANTS: A total of 486 unrelated patients with schizophrenia and 514 unrelated control individuals recruited from a northern Swedish isolated population. MAIN OUTCOME MEASURES: Association between markers and disease. RESULTS: Analysis of the Hap(ICE) markers showed the association of a 7-marker and 2-microsatellite haplotype, different from the haplotypes associated in the Icelandic population and overrepresented in northern Swedish control individuals. Subsequently, a more detailed analysis that included all 37 genotyped SNPs was performed by investigating haplotypic association, dependent and independent of LD block structure. We found significant association with 5 SNPs located in the second intron of NRG1 (.007 = P = .04). Also, 2-, 3-, and 4-SNP windows that comprise these SNPs were associated (P < 3 x 10(-4)). One protective haplotype (0% vs 1.8%; P <5 x 10(-5)) and 1 disease risk-causing haplotype (40.4% vs 34.9%, P = .02) were defined. CONCLUSION: The NRG1 gene contributes to the susceptibility for schizophrenia in the northern Swedish population.