scholarly journals Investigation of an LPA KIV-2 nonsense mutation in 11,000 individuals: the importance of linkage disequilibrium structure in LPA genetics

2019 ◽  
Author(s):  
Silvia Di Maio ◽  
Gertraud Streiter ◽  
Rebecca Grüneis ◽  
Claudia Lamina ◽  
Manuel Maglione ◽  
...  
Keyword(s):  
Nonsense Mutation ◽  
Association Studies ◽  
Plasma Concentrations ◽  
Splice Site Mutation ◽  
Epidemiological Studies ◽  
Splice Mutation ◽  
Genome Wide Association Studies ◽  
Site Mutation ◽  
Functional Variants ◽  
Variant Frequency

AbstractObjectiveElevated Lp(a) plasma concentrations are determined mainly genetically by the LPA gene locus, but up to 70% of the coding sequence is located in the so-called “kringle IV type 2” (KIV-2) copy number variation. This region is not resolved by common genotyping technologies and large epidemiological studies on this region are therefore missing. The Arg21Ter variant (R21X, variant frequency ≈2%) is a functional variant in this region, but it has never been analyzed in large cohorts and is it unknown whether it is captured by genome-wide association studies.Approach and ResultsWe developed a highly sensitive allele-specific qPCR assay and genotyped R21X in 10,910 individuals from three populations (GCKD, KORA F3, KORA F4). R21X carriers showed significantly lower mean Lp(a) concentrations (−11.7 mg/dL [−15.5;−7.82], p=3.39e-32). Of particular note, virtually all R21X carriers also carried the splice mutation rs41272114 (D’=0.957, R2=0.275), as confirmed by pulsed-field gel electrophoresis and long-range haplotyping. This proposes that the R21X mutation arose on the background of the rs41272114 splice variant.ConclusionsWe performed the largest epidemiological study on an LPA KIV-2 variant so far. Interestingly, R21X is located on the same haplotype as the splice mutation rs41272114, creating “double-null” LPA alleles that are inactivated by two independent mutations. The effect of the R21X nonsense mutation can thus not be discerned from the effect of rs41272114 splice site mutation. This emphasizes the importance of assessing the complex LD structure within LPA even for functional variants.

scholarly journals Genetic Contribution of Endometriosis to the Risk of Developing Hormone-Related Cancers

2021 ◽  
Vol 22 (11) ◽  
pp. 6083
Author(s):  
Aintzane Rueda-Martínez ◽  
Aiara Garitazelaia ◽  
Ariadna Cilleros-Portet ◽  
Sergi Marí ◽  
Rebeca Arauzo ◽  
...  
Keyword(s):  
Mendelian Randomization ◽  
Clear Cell ◽  
Association Studies ◽  
Epidemiological Data ◽  
Epidemiological Studies ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Genomic Analyses ◽  
Gynecological Disorder ◽  
Robust Evidence

Endometriosis is a common gynecological disorder that has been associated with endometrial, breast and epithelial ovarian cancers in epidemiological studies. Since complex diseases are a result of multiple environmental and genetic factors, we hypothesized that the biological mechanism underlying their comorbidity might be explained, at least in part, by shared genetics. To assess their potential genetic relationship, we performed a two-sample mendelian randomization (2SMR) analysis on results from public genome-wide association studies (GWAS). This analysis confirmed previously reported genetic pleiotropy between endometriosis and endometrial cancer. We present robust evidence supporting a causal genetic association between endometriosis and ovarian cancer, particularly with the clear cell and endometrioid subtypes. Our study also identified genetic variants that could explain those associations, opening the door to further functional experiments. Overall, this work demonstrates the value of genomic analyses to support epidemiological data, and to identify targets of relevance in multiple disorders.

scholarly journals MORFEE: a new tool for detecting and annotating single nucleotide variants creating premature ATG codons from VCF files

2020 ◽  
Author(s):  
Dylan Aïssi ◽  
Omar Soukarieh ◽  
Carole Proust ◽  
Beatrice Jaspard-Vinassa ◽  
Pierre Fautrad ◽  
...  
Keyword(s):  
Stop Codon ◽  
Association Studies ◽  
Premature Stop Codon ◽  
Open Reading Frames ◽  
Strong Impact ◽  
Genome Wide Association Studies ◽  
Single Nucleotide Variants ◽  
Functional Variants ◽  
Genome Wide ◽  
Upstream Open Reading Frames

AbstractSummaryVariants in 5’UTR regions that create upstream translation initiation AUG codons are a class of neglected non coding variations. When they associate with a premature stop codon and create upstream open reading frames (uORFs) whose translation competes with that of natural proteins, they can have strong impact on human diseases. We here describe MORFEE, a new bioinformatics tool that detects, annotates and predicts, from a standard VCF file, the creation of uORF by any 5’UTR variants on uORF creation. MORFEE was applied to two genomic resources and identified candidate functional variants that could explain statistical association signals observed in the context of Genome Wide Association Studies or could be responsible for rare forms of diseases. In conclusion MORFEE is an easy-to-use tool complementary to existing ones that can help resolving genetic investigations that remained so far unfruitful.Availability and implementationMORFEE is written in R with code and package available at https://github.com/daissi/[email protected]; [email protected]

The Yin and Yang of High-density Lipoprotein and Atherosclerotic Cardiovascular Disease: Focusing on Functionality and Cholesterol Efflux to Reframe the HDL Hypothesis

2021 ◽  
Vol 28 ◽  
Author(s):  
Shiva Ganjali ◽  
Gerald F. Watts ◽  
Maciej Banach ◽  
Željko Reiner ◽  
Petr Nachtigal ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
High Density Lipoprotein ◽  
Cholesterol Efflux ◽  
Association Studies ◽  
Plasma Concentrations ◽  
Density Lipoprotein ◽  
High Density ◽  
Atherosclerotic Cardiovascular Disease ◽  
Genome Wide Association Studies ◽  
Increased Risk

Abstract: The inverse relationship between low plasma high-density lipoprotein cholesterol (HDL-C) concentrations and increased risk of Atherosclerotic Cardiovascular Disease (ASCVD) is well-known. However, plasma HDL-C concentrations are highly variable in subjects with ASCVD. In clinical outcome trials, pharmacotherapies that increase HDL-C concentrations are not associated with a reduction in ASCVD events. A causal relationship between HDL-C and ASCVD has also been questioned by Mendelian randomization studies and genome-wide association studies of genetic variants associated with plasma HDL-C concentrations. The U-shaped association between plasma HDL-C concentrations and mortality observed in several epidemiological studies implicates both low and very high plasma HDL-C concentrations in the etiology of ASCVD and non-ASCVD mortality. These data do not collectively support a causal association between HDL-C and ASCVD risk. Therefore, the hypothesis concerning the association between HDL and ASCVD has shifted from focus on plasma concentrations to the concept of functionality, in particular cellular cholesterol efflux and HDL holoparticle transport. In this review, we focus on these new concepts and provide a new framework for understanding and testing the role of HDL in ASCVD.

Abstract 18374: Targeted Sequencing and Massively Parallel Reporter Assay Identify the Functional Variation Underlying the 4q25 Locus for Atrial Fibrillation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Nathan R Tucker ◽  
Jiangchuan Ye ◽  
Honghuang Lin ◽  
Michael A McLellan ◽  
Emelia J Benjamin ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Association Studies ◽  
Targeted Sequencing ◽  
Massively Parallel ◽  
Genome Wide Association Studies ◽  
Sequencing Analysis ◽  
Reporter Assay ◽  
Enhancer Activity ◽  
Functional Variants ◽  
Massively Parallel Reporter Assay

Introduction: Genome-wide association studies have identified 14 independent loci for atrial fibrillation (AF). The 4q25 locus upstream of the left-right asymmetry gene PITX2 is, by far, the strongest association signal for AF. However, as with most GWAS loci, the functional variants are noncoding, presumed to be regulatory, and remain unknown. We therefore sought to rapidly identify the functional variants at an AF locus by combining high throughput sequencing and massively parallel reporter assays. Methods and Results: We sequenced a ~750kb region encompassing the PITX2 locus in 462 individuals with early-onset AF from the MGH AF Study and 464 referents from the Framingham Heart Study. The SNP most significantly associated with AF in our sequenced sample was rs2129983, which is 140kb from PITX2 (OR=2.43, P =8.9X10 -16 ). rs2129983 is approximately 1.7kb from the most significantly associated SNP in a prior AF GWAS, rs6817105 (r 2 =0.52). From the targeted sequencing analysis, we identified 262 SNVs with a MAF >0.5% within a genomic region bounded by SNPs with an r2 greater than 0.4 with the top variant. To identify functional variants, we then utilized a massively parallel reporter assay (MPRA) in order to measure enhancer activity at each SNP across the entire AF locus. In both HL-1 and C2C12 myoblasts, MPRA identified many distinct SNP regions with differential enhancer activity. Using AF-association status as a standard, we were able to identify a series of variants that have both differential activity in either cell line tested and also a high level of association (rs17042076, rs4469143). Mechanistically, these functional SNPs are predicted to alter transcription factor binding. Conclusions: We have comprehensively identified the AF-associated variation at 4q25 and determined which of these variants are functional through differential enhancer activity. Here, in addition to identifying the causative variation for AF at 4q25, we provide a generalizable pathway for translating this work to other loci, a method that could expedite the identification of causative genetic variants at other disease loci.

scholarly journals Genetics of COPD

2020 ◽  
Vol 82 (1) ◽  
pp. 413-431 ◽  
Author(s):  
Edwin K. Silverman
Keyword(s):  
Association Studies ◽  
Chronic Obstructive ◽  
Genome Wide Association Studies ◽  
Obstructive Pulmonary Disease ◽  
Functional Variants ◽  
Genome Wide ◽  
Antitrypsin Deficiency ◽  
Alpha 1 Antitrypsin Deficiency ◽  
Alpha 1 Antitrypsin ◽  
Genomic Regions

Although chronic obstructive pulmonary disease (COPD) risk is strongly influenced by cigarette smoking, genetic factors are also important determinants of COPD. In addition to Mendelian syndromes such as alpha-1 antitrypsin deficiency, many genomic regions that influence COPD susceptibility have been identified in genome-wide association studies. Similarly, multiple genomic regions associated with COPD-related phenotypes, such as quantitative emphysema measures, have been found. Identifying the functional variants and key genes within these association regions remains a major challenge. However, newly identified COPD susceptibility genes are already providing novel insights into COPD pathogenesis. Network-based approaches that leverage these genetic discoveries have the potential to assist in decoding the complex genetic architecture of COPD.

scholarly journals Chronic lymphocytic leukemia (CLL) risk is mediated by multiple enhancer variants within CLL risk loci

2020 ◽  
Vol 29 (16) ◽  
pp. 2761-2774
Author(s):  
Huihuang Yan ◽  
Shulan Tian ◽  
Geffen Kleinstern ◽  
Zhiquan Wang ◽  
Jeong-Heon Lee ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Immune Cell ◽  
Association Studies ◽  
Cell Types ◽  
Lymphocytic Leukemia ◽  
Type I ◽  
Genome Wide Association Studies ◽  
Gene Promoters ◽  
Functional Variants ◽  
Increased Risk

Abstract Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in Western countries. It has a strong genetic basis, showing a ~ 8-fold increased risk of CLL in first-degree relatives. Genome-wide association studies (GWAS) have identified 41 risk variants across 41 loci. However, for a majority of the loci, the functional variants and the mechanisms underlying their causal roles remain undefined. Here, we examined the genetic and epigenetic features associated with 12 index variants, along with any correlated (r2 ≥ 0.5) variants, at the CLL risk loci located outside of gene promoters. Based on publicly available ChIP-seq and chromatin accessibility data as well as our own ChIP-seq data from CLL patients, we identified six candidate functional variants at six loci and at least two candidate functional variants at each of the remaining six loci. The functional variants are predominantly located within enhancers or super-enhancers, including bi-directionally transcribed enhancers, which are often restricted to immune cell types. Furthermore, we found that, at 78% of the functional variants, the alternative alleles altered the transcription factor binding motifs or histone modifications, indicating the involvement of these variants in the change of local chromatin state. Finally, the enhancers carrying functional variants physically interacted with genes enriched in the type I interferon signaling pathway, apoptosis, or TP53 network that are known to play key roles in CLL. These results support the regulatory roles for inherited noncoding variants in the pathogenesis of CLL.

scholarly journals Identification of novel non-synonymous variants associated with type 2 diabetes-related metabolites in Korean population

2019 ◽  
Vol 39 (10) ◽  
Author(s):  
Tae-Joon Park ◽  
Heun-Sik Lee ◽  
Young Jin Kim ◽  
Bong-Jo Kim
Keyword(s):  
Type 2 Diabetes ◽  
Genetic Variants ◽  
Multiple Testing ◽  
Association Studies ◽  
Linear Regression Analysis ◽  
Genetic Regulation ◽  
Genome Wide Association Studies ◽  
Functional Variants ◽  
Genome Wide

Abstract Metabolome-genome wide association studies (mGWASs) are useful for understanding the genetic regulation of metabolites in complex diseases, including type 2 diabetes (T2D). Numerous genetic variants associated with T2D-related metabolites have been identified in previous mGWASs; however, these analyses seem to have difficulty in detecting the genetic variants with functional effects. An exome array focussed on potentially functional variants is an alternative platform to obtain insight into the genetics of biochemical conversion processes. In the present study, we performed an mGWAS using 27,140 non-synonymous variants included in the Illumina HumanExome BeadChip and nine T2D-related metabolites identified by a targetted metabolomics approach to evaluate 2,338 Korean individuals from the Korea Association REsource (KARE) cohort. A linear regression analysis controlling for age, sex, BMI, and T2D status as covariates was performed to identify novel non-synonymous variants associated with T2D-related metabolites. We found significant associations between glycine and CPS1 (rs1047883) and PC ae C36:0 and CYP4F2 (rs2108622) variants (P<2.05 × 10−7, after the Bonferroni correction for multiple testing). One of the two significantly associated variants, rs1047883 was newly identified whereas rs2108622 had been previously reported to be associated with T2D-related traits. These findings expand our understanding of the genetic determinants of T2D-related metabolites and provide a basis for further functional validation.

scholarly journals Identification of Genetic Risk Factors for Familial Urinary Bladder Cancer: An Exome Sequencing Study

2021 ◽  
pp. 1830-1839
Author(s):  
Alexander Pemov ◽  
Talia Wegman-Ostrosky ◽  
Jung Kim ◽  
Stella Koutros ◽  
Brenna Douthitt ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Dna Repair ◽  
Urinary Bladder ◽  
Association Studies ◽  
Cellular Metabolism ◽  
Urinary Bladder Cancer ◽  
Pathogenic Variant ◽  
The Cancer Genome Atlas ◽  
Genome Wide Association Studies ◽  
Variant Frequency

PURPOSE Previous studies have shown an approximately two-fold elevation in the relative risk of urinary bladder cancer (UBC) among people with a family history that could not be entirely explained by shared environmental exposures, thus suggesting a genetic component in its predisposition. Multiple genome-wide association studies and recent gene panel sequencing studies identified several genetic loci that are associated with UBC risk; however, the list of UBC-associated variants and genes is incomplete. MATERIALS AND METHODS We exome sequenced eight patients from three multiplex UBC pedigrees and a group of 77 unrelated familial UBC cases matched to 241 cancer-free controls. In addition, we examined pathogenic germline variation in 444 candidate genes in 392 The Cancer Genome Atlas UBC cases. RESULTS In the pedigrees, segregating variants were family-specific although the identified genes clustered in common pathways, most notably DNA repair ( MLH1 and MSH2) and cellular metabolism ( IDH1 and ME1). In the familial UBC group, the proportion of pathogenic and likely pathogenic variants was significantly higher in cases compared with controls ( P = .003). Pathogenic and likely pathogenic variant load was also significantly increased in genes involved in cilia biogenesis ( P = .001). In addition, a pathogenic variant in CHEK2 (NM_007194.4:c.1100del; p.T367Mfs*15) was over-represented in cases (variant frequency = 2.6%; 95% CI, 0.71 to 6.52) compared with controls (variant frequency = 0.21%; 95% CI, 0.01 to 1.15), but was not statistically significant. CONCLUSION These results point to a complex polygenic predisposition to UBC. Despite heterogeneity, the genes cluster in several biologically relevant pathways and processes, for example, DNA repair, cilia biogenesis, and cellular metabolism. Larger studies are required to determine the importance of CHEK2 in UBC etiology.

scholarly journals Causal Association between Serum Thyroid-Stimulating Hormone and Obesity: A Bidirectional Mendelian Randomization Study

2021 ◽  
Author(s):  
Xichang Wang ◽  
Xiaotong Gao ◽  
Yutong Han ◽  
Fan Zhang ◽  
Zheyu Lin ◽  
...  
Keyword(s):  
Mendelian Randomization ◽  
Association Studies ◽  
Epidemiological Studies ◽  
Thyroid Stimulating Hormone ◽  
Genome Wide Association Studies ◽  
Causal Association ◽  
Free Triiodothyronine ◽  
The Impact ◽  
Serum Tsh ◽  
Stimulating Hormone

Abstract Context The association between serum thyroid-stimulating hormone (TSH) and obesity traits has been investigated previously in several epidemiological studies. However, the underlying causal association has not been established. Objective To determine and analyze the causal association between serum TSH level and obesity-related traits (BMI and obesity). Design, Setting, Participants The latest genome-wide association studies (GWASs) on TSH, BMI and obesity were searched to obtain full statistics. Bidirectional two-sample Mendelian randomization (MR) was performed to explore the causal relationship between serum TSH and BMI and obesity. The inverse variance-weighted (IVW) and MR-Egger methods were used to combine the estimation for each SNP. Based on the preliminary MR results, free thyroxine (fT4) and free triiodothyronine (fT3) levels were also set as outcomes to further analyze the impact of BMI on them. Main Outcome Measures BMI and obesity were treated as the outcomes to evaluate the effect of serum TSH on them, and TSH was set as the outcome to estimate the effect of BMI and obesity on it. Results Both IVW and MR-Egger results indicated that genetically driven serum TSH did not causally lead to changes in BMI or obesity. Moreover, the IVW method showed that the TSH level could be significantly elevated by genetically predicted high BMI (β=0.038, se=0.013, p=0.004). In further MR analysis, the IVW method indicated that BMI could causally increase the fT3 (β=10.123, se=2.523, p&lt;0.001) while not significantly affecting the fT4 level. Conclusion Together with fT3, TSH can be significantly elevated by an increase in genetically driven BMI.

scholarly journals Truncating mutation in TANC2 in a Chinese boy associated with Lennox-Gastaut syndrome: a case report

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yang Tian ◽  
Zhen Shi ◽  
Chi Hou ◽  
Wenjuan Li ◽  
Xiuying Wang ◽  
...  
Keyword(s):  
Antiepileptic Drugs ◽  
Nonsense Mutation ◽  
Synapse Formation ◽  
De Novo ◽  
Association Studies ◽  
Gene Mutations ◽  
Epileptic Encephalopathy ◽  
Scaffolding Protein ◽  
Genome Wide Association Studies ◽  
Truncating Mutation

Abstract Background Lennox-Gastaut syndrome (LGS) is a severe epileptic encephalopathy that can be caused by brain malformations or genetic mutations. Recently, genome-wide association studies have led to the identification of novel mutations associated with LGS. The TANC2 gene, encodes a synaptic scaffolding protein that interacts with other proteins at the postsynaptic density to regulate dendritic spines and excitatory synapse formation. The TANC2 gene mutations were reported in neurodevelopmental disorders and epilepsy but not in LGS ever. Case presentation Here we describe the case of a boy with LGS who presented with multiple seizure patterns, such as myoclonic, atonic, atypical absence, generalized tonic-clonic, focal seizures, and notable cognitive and motor regression. The seizures were refractory to many antiepileptic drugs. He got seizure-free with ketogenic diet combined with antiepileptic drugs. A de novo nonsense mutation c.4321C > T(p.Gln1441Ter) in TANC2 gene was identified by the whole-exome sequencing and confirmed by Sanger sequencing. Conclusion We described the first Chinese case with LGS associated to a de novo nonsense mutation c.4321C > T(p.Gln1441Ter) in TANC2 gene, which would expand the clinical spectrum related to TANC2 mutations and contribute to better understanding of genotype-phenotype relationship to guide precision medicine.

Sign in / Sign up

Export Citation Format

Share Document