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CYP2C19 Polymorphisms in Indonesia: Comparison among Ethnicities and the Association with Clinical Outcomes. BIOLOGY 2021; 10:biology10040300. [PMID: 33917299 PMCID: PMC8067412 DOI: 10.3390/biology10040300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 01/06/2023]
Abstract
Simple Summary CYP2C19 is known as an enzyme primarily responsible for metabolizing various drugs, such as proton pump inhibitor, antiplatelet, anti-epileptic, and anticoagulant. CYP2C19 is known to be polymorphic and can result in the clinical efficacy of drugs. To examine the prevalence and the distribution of the CYP2C19 genetic polymorphisms in Indonesia, we performed polymerase chain reaction-restriction fragment length polymorphism to the genomic DNA of Indonesian participants. In addition, we also analyzed the distribution of CYP2C19 polymorphisms among ethnicities and clinical outcomes. We found that the prevalence of intermediate metabolizers were the highest in Indonesia, followed by rapid metabolizers and poor metabolizers, respectively. The distribution of metabolizer groups were different between ethnic groups in Indonesia. Therefore, dosage adjustment should be considered when administering drugs-affected by CYP2C19 in Indonesia. The results presented in this study showed the distribution of CYP2C19 variant alleles at the population level in Indonesia and might be used as a consideration for providing personalized treatment in clinical practice. Abstract CYP2C19 polymorphisms are important factors for proton pump inhibitor-based therapy. We examined the CYP2C19 genotypes and analyzed the distribution among ethnicities and clinical outcomes in Indonesia. We employed the polymerase chain reaction-restriction fragment length polymorphism method to determine the CYP2C19 genotypes and evaluated inflammation severity with the updated Sydney system. For CYP2C19*2, 46.4% were the homozygous wild-type allele, 14.5% were the homozygous mutated allele, and 39.2% were the heterozygous allele. For CYP2C19*3, 88.6% were the homozygous wild-type allele, 2.4% were the homozygous mutated allele, and 9.0% were the heterozygous allele. Overall, the prevalence of rapid, intermediate, and poor metabolizers in Indonesia was 38.5, 41.6, and 19.9%, respectively. In the poor metabolizer group, the frequency of allele *2 (78.8%) was higher than the frequency of allele *3 (21.2%). The Papuan had a significantly higher likelihood of possessing poor metabolizers than the Balinese (OR 11.0; P = 0.002). The prevalence of poor metabolizers was lower compared with the rapid and intermediate metabolizers among patients with gastritis and gastroesophageal reflux disease. Intermediate metabolizers had the highest prevalence, followed by rapid metabolizers and poor metabolizers. Dosage adjustment should therefore be considered when administering proton pump inhibitor-based therapy in Indonesia.
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Hanh NTH, Nhung BT, Hop LT, Tuyet LT, Dao DTA, Thu NTT, Binh TQ. The APOA5-rs662799 Polymorphism Is a Determinant of Dyslipidemia in Vietnamese Primary School Children. Lipids 2020; 55:683-691. [PMID: 32777089 DOI: 10.1002/lipd.12270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 05/10/2020] [Accepted: 07/01/2020] [Indexed: 11/05/2022]
Abstract
Apolipoprotein A-V encoded by apolipoprotein 5 (APOA5) gene plays an important role in lipid metabolism, especially in the regulation of plasma triglycerol levels. The study aimed to evaluate the association of the APOA5-rs662799 polymorphism with dyslipidemia in Vietnamese children and the potential modification of obesity-related traits (body mass index, waist circumference, hip circumference, and waist-to-hip ratio) on this association. A case-control study was conducted with a total of 154 dyslipidemia cases and 389 controls at the age of 6 to 10 recruited at 31 primary schools in Hanoi city of Vietnam. Genotype for APOA5-rs662799 polymorphism was determined by the restriction fragment length polymorphism analysis. The association of APOA5-rs662799 polymorphism with dyslipidemia adjusting for age, sex, residence, and obesity-related traits was analyzed by binary logistic regression analysis. The results showed that in comparison with T/T and T/C carriers, the C/C carriers had a higher concentration of serum TAG in cases (p =0.049). Carriers of the C allele (C/C + T/C) had higher risk for developing dyslipidemia and hypertriglyceridemia than subjects with T/T genotype (odds ratio, OR = 1.7, p =0.0062 and OR = 1.6, p = 0.026, respectively). The association remained significant after adjusting for age, gender, residence, and obesity status (OR = 1.75, p = 0.006 and OR = 1.53, p = 0.049, respectively) or other obesity-related traits. The study suggested that the APOA5-rs662799 polymorphism may be a determinant of dyslipidemia and hypertriglyceridemia in Vietnamese children, independent of obesity-related traits.
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Affiliation(s)
- Nguyen T H Hanh
- Department of Biology, Hanoi National University of Education, 136 Xuan Thuy Street, Hanoi, 100000, Vietnam
| | - Bui T Nhung
- National Institute of Nutrition, 48B Tang Bat Ho Street, Hanoi, 112807, Vietnam
| | - Le T Hop
- National Institute of Nutrition, 48B Tang Bat Ho Street, Hanoi, 112807, Vietnam
| | - Le T Tuyet
- Department of Biology, Hanoi National University of Education, 136 Xuan Thuy Street, Hanoi, 100000, Vietnam
| | - Duong T A Dao
- Department of Biology, Hanoi National University of Education, 136 Xuan Thuy Street, Hanoi, 100000, Vietnam
| | - Nguyen T T Thu
- Department of Biology, Hanoi National University of Education, 136 Xuan Thuy Street, Hanoi, 100000, Vietnam
| | - Tran Quang Binh
- National Institute of Nutrition, 48B Tang Bat Ho Street, Hanoi, 112807, Vietnam.,Dinh Tien Hoang Institute of Medicine, 20 Cat Linh Street, Hanoi, 100000, Vietnam
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Shah R, Sharma V, Bhat A, Singh H, Sharma I, Verma S, Bhat GR, Sharma B, Bakshi D, Kumar R, Dar NA. MassARRAY analysis of twelve cancer related SNPs in esophageal squamous cell carcinoma in J&K, India. BMC Cancer 2020; 20:497. [PMID: 32487238 PMCID: PMC7268327 DOI: 10.1186/s12885-020-06991-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 05/21/2020] [Indexed: 02/06/2023] Open
Abstract
Background MassARRAY (Agena Bioscience™) combines competitive PCR with MALDI-TOF mass spectrometry (MS) analysis that gives highly accurate, sensitive, and high-throughput methods for the quantitative analysis of variation of gene expression in multiple samples. SNPs (Single Nucleotide Polymorphisms) have a very high potential of discovering disease-gene relationships. SNP-genotyping through MassARRAY is not only a cost-effective genotyping method but also provides a platform to validate variants observed through a high-throughput Next-generation sequencing (NGS). Methods In the present study, we have incorporated the use of matrix-assisted laser desorption/ionization-time of flight, mass spectrometry (MALDI-TOF) as a tool for differentiating genotypes based on the mass of variant. We have performed multiplex PCR and genotyped 12 SNPs in 758 samples (166 cases and 592 controls). The 12 studied SNPs were chosen with a rationale for their association with multiple cancers in literature. Results This is the first study to explore these SNPs with esophageal cancer within the J&K population. Out of 12 SNPs, two SNPs rs12190287 of TCF21 and rs10046 of CYP19A1 were significantly associated with esophageal cancer with Odds Ratio (OR) 1.412 (1.09–1.8 at 95% CI, p = 0.008) and 1.54 (1.21–2.072 at 95% CI, p = 0.0007) within the population of Jammu and Kashmir. Conclusion We explored 12 SNPs that were found to be associated with multiple cancers in literature with esophageal cancer within the population of J&K. This is the first study to find the relation of these SNPs with ESCC within the studied population. This study explores the relation of genetic and environmental factors with the ESCC susceptibility.
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Affiliation(s)
- Ruchi Shah
- School of Biotechnology, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India.
| | - Varun Sharma
- Human Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Amrita Bhat
- Cancer Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Hemender Singh
- Human Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Indu Sharma
- Human Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Sonali Verma
- Cancer Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Gh Rasool Bhat
- Cancer Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Bhanu Sharma
- Cancer Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Divya Bakshi
- Cancer Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Rakesh Kumar
- Cancer Genetics Research Group, Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Nazir Ahmed Dar
- Department of Biochemistry, University of Kashmir, Srinagar, Jammu and Kashmir, 180001, India.
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Kerr KF, Morenz ER, Thiessen-Philbrook H, Coca SG, Wilson FP, Reese PP, Parikh CR. Quantifying Donor Effects on Transplant Outcomes Using Kidney Pairs from Deceased Donors. Clin J Am Soc Nephrol 2019; 14:1781-1787. [PMID: 31676539 PMCID: PMC6895487 DOI: 10.2215/cjn.03810319] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 10/07/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES In kidney transplantation, the relative contribution of donor versus other factors on clinical outcomes is unknown. We sought to quantify overall donor effects on transplant outcomes for kidney donations from deceased donors. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS For paired donations from deceased donors resulting in transplants to different recipients, the magnitude of donor effects can be quantified by examining the excess of concordant outcomes within kidney pairs beyond chance concordance. Using data from the Organ Procurement and Transplantation Network between the years 2013 and 2017, we examined concordance measures for delayed graft function, death-censored 1-year graft failure, and death-censored 3-year graft failure. The concordance measures were excess relative risk, excess absolute risk, and the fixation index (where zero is no concordance and one is perfect concordance). We further examined concordance in strata of kidneys with similar values of the Kidney Donor Profile Index, a common metric of organ quality. RESULTS If the transplant of the kidney mate resulted in delayed graft function, risk for delayed graft function was 19% higher (95% confidence interval [95% CI], 18% to 20%), or 1.76-fold higher (95% CI, 1.73- to 1.80-fold), than baseline. If a kidney graft failed within 1 year, then the kidney mate's risk of failure was 6% higher (95% CI, 4% to 9%), or 2.85-fold higher (95% CI, 2.25- to 3.48-fold), than baseline. For 3-year graft failure, the excess absolute risk was 7% (95% CI, 4% to 10%) but excess relative risk was smaller, 1.91-fold (95% CI, 1.56- to 2.28-fold). Fixation indices were 0.25 for delayed graft function (95% CI, 0.24 to 0.27), 0.07 for 1-year graft failure (95% CI, 0.04 to 0.09), and 0.07 for 3-year graft failure (95% CI, 0.04 to 0.10). Results were similar in strata of kidneys with a similar Kidney Donor Profile Index. CONCLUSIONS Overall results indicated that the donor constitution has small or moderate effect on post-transplant clinical outcomes.
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Affiliation(s)
- Kathleen F Kerr
- Department of Biostatistics, University of Washington, Seattle, Washington
| | - Eric R Morenz
- Department of Biostatistics, University of Washington, Seattle, Washington
| | | | - Steven G Coca
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - F Perry Wilson
- Program of Applied Translational Research, Department of Internal Medicine, Section of Nephrology, Yale University School of Medicine, New Haven, Connecticut; and
| | - Peter P Reese
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Chirag R Parikh
- Division of Nephrology, School of Medicine, Johns Hopkins University, Baltimore, Maryland;
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Broeckx BJG, Derrien T, Mottier S, Wucher V, Cadieu E, Hédan B, Le Béguec C, Botherel N, Lindblad-Toh K, Saunders JH, Deforce D, André C, Peelman L, Hitte C. An exome sequencing based approach for genome-wide association studies in the dog. Sci Rep 2017; 7:15680. [PMID: 29142306 PMCID: PMC5688105 DOI: 10.1038/s41598-017-15947-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 11/04/2017] [Indexed: 12/12/2022] Open
Abstract
Genome-wide association studies (GWAS) are widely used to identify loci associated with phenotypic traits in the domestic dog that has emerged as a model for Mendelian and complex traits. However, a disadvantage of GWAS is that it always requires subsequent fine-mapping or sequencing to pinpoint causal mutations. Here, we performed whole exome sequencing (WES) and canine high-density (cHD) SNP genotyping of 28 dogs from 3 breeds to compare the SNP and linkage disequilibrium characteristics together with the power and mapping precision of exome-guided GWAS (EG-GWAS) versus cHD-based GWAS. Using simulated phenotypes, we showed that EG-GWAS has a higher power than cHD to detect associations within target regions and less power outside target regions, with power being influenced further by sample size and SNP density. We analyzed two real phenotypes (hair length and furnishing), that are fixed in certain breeds to characterize mapping precision of the known causal mutations. EG-GWAS identified the associated exonic and 3'UTR variants within the FGF5 and RSPO2 genes, respectively, with only a few samples per breed. In conclusion, we demonstrated that EG-GWAS can identify loci associated with Mendelian phenotypes both within and across breeds.
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Affiliation(s)
- Bart J G Broeckx
- Laboratory of Animal Genetics, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - Thomas Derrien
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France
| | - Stéphanie Mottier
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France
| | - Valentin Wucher
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France
| | - Edouard Cadieu
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France
| | - Benoît Hédan
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France
| | - Céline Le Béguec
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France
| | - Nadine Botherel
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France
| | - Kerstin Lindblad-Toh
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Jimmy H Saunders
- Department of Medical Imaging and Orthopedics, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Dieter Deforce
- Laboratory of Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Catherine André
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France
| | - Luc Peelman
- Laboratory of Animal Genetics, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Christophe Hitte
- Institut de Génétique et Développement de Rennes, CNRS-URM6290, Université Rennes1, Rennes, France.
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Kalungi A, Seedat S, Hemmings SMJ, van der Merwe L, Joloba ML, Nanteza A, Nakassujja N, Birabwa H, Serwanga J, Kaleebu P, Kinyanda E. Association between serotonin transporter gene polymorphisms and increased suicidal risk among HIV positive patients in Uganda. BMC Genet 2017; 18:71. [PMID: 28743254 PMCID: PMC5526289 DOI: 10.1186/s12863-017-0538-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/18/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Persons living with HIV/AIDS (PLWHA) are at an increased risk of suicide. Increased suicidal risk is a predictor of future attempted and completed suicides and has been associated with poor quality of life and poor adherence with antiretroviral therapy. Clinical risk factors have low predictive value for suicide, hence the interest in potential neurobiological correlates and specific heritable markers of suicide vulnerability. The serotonin transporter gene has previously been implicated in the aetiology of increased suicidal risk in non-HIV infected study populations and its variations may provide a platform for identifying genetic risk for suicidality among PLWHA. The present cross-sectional study aimed at identifying two common genetic variants of the serotonin transporter gene and their association with increased suicidal risk among human immunodeficiency virus (HIV)-positive adults in Uganda. RESULTS The prevalence of increased suicidal risk (defined as moderate to high risk suicidality on the suicidality module of the Mini Neuropsychiatric Interview (M.I.N.I) was 3.3% (95% CI, 2.0-5.3). The 5-HTTLPR was found to be associated with increased suicidal risk before Bonferroni correction (p-value = 0.0174). A protective effect on increased suicidal risk was found for the 5-HTTLPR/rs25531 S A allele (p-value = 0.0046)- which directs reduced expression of the serotonin transporter gene (5-HTT). CONCLUSION The S A allele at the 5-HTTLPR/rs25531 locus is associated with increased suicidal risk among Ugandan PLWHA. Further studies are needed to validate this finding in Ugandan and other sub-Saharan samples.
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Affiliation(s)
- Allan Kalungi
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine, Animal Resources and Biosafety (COVAB), Makerere University, Kampala, Uganda
- Mental Health Project, Medical Research Council/Uganda Virus Research Institute (MRC/UVRI) Research Unit on AIDS, Kampala, Uganda
| | - Soraya Seedat
- Department of Psychiatry, Stellenbosch University, Cape Town, South Africa
| | - Sian M. J. Hemmings
- Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, University of Stellenbosch, Cape Town, South Africa
| | - Lize van der Merwe
- Department of Statistics, University of the Western Cape, Cape Town, South Africa
| | - Moses L. Joloba
- School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Ann Nanteza
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine, Animal Resources and Biosafety (COVAB), Makerere University, Kampala, Uganda
| | - Noeline Nakassujja
- Department of Psychiatry, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Harriet Birabwa
- Butabika National Psychiatric Referral Hospital, Kampala, Uganda
| | - Jennifer Serwanga
- Basic Science Programme, MRC/UVRI Uganda Research Unit on AIDS, Kampala, Uganda
| | - Pontiano Kaleebu
- Basic Science Programme, MRC/UVRI Uganda Research Unit on AIDS, Kampala, Uganda
| | - Eugene Kinyanda
- Mental Health Project, Medical Research Council/Uganda Virus Research Institute (MRC/UVRI) Research Unit on AIDS, Kampala, Uganda
- Department of Psychiatry, College of Health Sciences, Makerere University, Kampala, Uganda
- Faculty of Epidemiology & Population Health, London School of Hygiene & Tropical Medicine, London, UK
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Dimou NL, Pantavou KG, Bagos PG. Apolipoprotein E Polymorphism and Left Ventricular Failure in Beta-Thalassemia: A Multivariate Meta-Analysis. Ann Hum Genet 2017; 81:213-223. [DOI: 10.1111/ahg.12203] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 06/05/2017] [Indexed: 01/06/2023]
Affiliation(s)
- Niki L. Dimou
- Department of Computer Science and Biomedical Informatics; University of Thessaly; Papasiopoulou 2-4 Lamia 35100 Greece
| | - Katerina G. Pantavou
- Department of Computer Science and Biomedical Informatics; University of Thessaly; Papasiopoulou 2-4 Lamia 35100 Greece
| | - Pantelis G. Bagos
- Department of Computer Science and Biomedical Informatics; University of Thessaly; Papasiopoulou 2-4 Lamia 35100 Greece
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Vaidyanathan V, Naidu V, Karunasinghe N, Jabed A, Pallati R, Marlow G, R. Ferguson L. SNP-SNP interactions as risk factors for aggressive prostate cancer. F1000Res 2017; 6:621. [PMID: 28580135 PMCID: PMC5437948 DOI: 10.12688/f1000research.11027.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/19/2017] [Indexed: 12/23/2022] Open
Abstract
Prostate cancer (PCa) is one of the most significant male health concerns worldwide. Single nucleotide polymorphisms (SNPs) are becoming increasingly strong candidate biomarkers for identifying susceptibility to PCa. We identified a number of SNPs reported in genome-wide association analyses (GWAS) as risk factors for aggressive PCa in various European populations, and then defined SNP-SNP interactions, using PLINK software, with nucleic acid samples from a New Zealand cohort. We used this approach to find a gene x environment marker for aggressive PCa, as although statistically gene x environment interactions can be adjusted for, it is highly impossible in practicality, and thus must be incorporated in the search for a reliable biomarker for PCa. We found two intronic SNPs statistically significantly interacting with each other as a risk for aggressive prostate cancer on being compared to healthy controls in a New Zealand population.
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Affiliation(s)
- Venkatesh Vaidyanathan
- Discipline of Nutrition and Dietetics, FM & HS, University of Auckland, Auckland, New Zealand
- Auckland Cancer Society Research Centre, Auckland, New Zealand
| | - Vijay Naidu
- School of Engineering,Computer and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand
| | | | - Anower Jabed
- Department of Molecular Medicine and Pathology, FM & HS, University of Auckland, Auckland, New Zealand
| | - Radha Pallati
- Discipline of Nutrition and Dietetics, FM & HS, University of Auckland, Auckland, New Zealand
| | - Gareth Marlow
- Experimental Cancer Medicine Centre, Cardiff University, Cardiff, UK
| | - Lynnette R. Ferguson
- Discipline of Nutrition and Dietetics, FM & HS, University of Auckland, Auckland, New Zealand
- Auckland Cancer Society Research Centre, Auckland, New Zealand
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Wang L, Graubard BI, Li Y. A composite likelihood approach in testing for Hardy Weinberg Equilibrium using family-based genetic survey data. Stat Med 2016; 35:5040-5050. [PMID: 27481259 PMCID: PMC7210008 DOI: 10.1002/sim.7044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 06/20/2016] [Accepted: 06/23/2016] [Indexed: 11/09/2022]
Abstract
In population-based household surveys, for example, the National Health and Nutrition Examination Survey, households are often sampled by stratified multistage cluster sampling, and multiple individuals related by blood are often sampled within households. Therefore, genetic data collected from these population-based household surveys, called National Genetic Household Surveys, can be correlated because of two levels of correlation. One level of correlation is caused by the multistage geographical cluster sampling and the other is caused by biological inheritance among participants within the same sampled family. In this paper, we develop an efficient Hardy Weinberg Equilibrium (HWE) test utilizing pairwise composite likelihood methods that incorporate the sample weighting effect induced by the differential selection probabilities in complex sample designs, as well as the two-level clustering (correlation) effects described above. Monte Carlo simulation studies show that the proposed HWE test maintains the nominal levels, and is more powerful than existing methods (Li et al. 2011) under various (non)informative sample designs that depend on genotypes (explicitly or implicitly), family relationships or both, especially when within-household sampling depends on the genotypes. The developed tests are further evaluated using simulated genetic data based on the Hispanic Health and Nutrition Survey. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Lingxiao Wang
- Joint Program in Survey Methodology, University of Maryland, College Park, MD, 20742, U.S.A
| | - Barry I Graubard
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, 20850, U.S.A
| | - Yan Li
- Joint Program in Survey Methodology, University of Maryland, College Park, MD, 20742, U.S.A..
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, 20850, U.S.A..
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Li Y, Li C, Gao J. Apolipoprotein C3 gene variants and the risk of coronary heart disease: A meta-analysis. Meta Gene 2016; 9:104-9. [PMID: 27331014 PMCID: PMC4908280 DOI: 10.1016/j.mgene.2016.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/22/2016] [Accepted: 04/22/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND It has been reported that three common loci, SstI, C-482T, and T-455C, in the apolipoprotein C3 (APOC3) gene might be associated with an increased risk of coronary heart disease (CHD). Considering the inconsistent results and ethnicity variations, we performed a systematic meta-analysis to evaluate the association between three single nucleotide polymorphisms (SNPs) and the risk of CHD. METHODS We searched HuGE Navigator and PubMed databases to screen for the related literature published before 25 September, 2015. Two independent reviewers extracted the data and assessed the study quality. A random-effect model was used to pool the effect size. RESULTS A total of 29 studies met inclusion criteria. Nineteen studies, including 11,186 subjects relative to SstI, five studies comprising 3727 subjects relative to C-482T, and nine studies with 6753 subjects relative to T-455C were included in the final analysis. A significant increase in CHD risk was observed in the SstI polymorphism (S2 versus S1: odds ratio [OR] = 1.30, 95% confidence interval [CI] 1.10-1.55. There was also a significant increasing trend of CHD risk in the T-455C polymorphism (C versus T: OR = 1.28, 95% CI 1.16-1.41. However, no associations between C-482T and CHD risk were found in this meta-analysis. CONCLUSIONS The pooled evidence suggests that two SNPs (SstI and T-455C) are associated with an increased risk of CHD. However, because of the limited sample size and heterogeneity, further large-scale and well-designed studies are needed to validate our findings.
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Affiliation(s)
- Yan Li
- Department of Epidemiology, Beijing An zhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China
| | - Chao Li
- Cardiovascular Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Jie Gao
- Surgical Intensive Care Unit, Beijing An zhen Hospital, Capital Medical University, Beijing 100029, China
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Vitamin D receptor Cdx-2-dependent response of central obesity to vitamin D intake in the subjects with type 2 diabetes: a randomised clinical trial. Br J Nutr 2015; 114:1375-84. [PMID: 26346470 DOI: 10.1017/s0007114515003049] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This study aimed to investigate the effects of daily intake of vitamin D-fortified yogurt drink (doogh) on central obesity indicators in subjects with type 2 diabetes (T2D) and the possible modulation of this effect by vitamin D receptor (VDR) Cdx-2 genotypes. A total of sixty T2D subjects were randomly allocated to two groups to receive either plain doogh (PD; n 29, containing 170 mg Ca and no vitamin D/250 ml) or vitamin D3-fortified doogh (FD; n 31, containing 170 mg Ca and 12·5 μg/250 ml) twice a day for 12 weeks. 25-hydroxyvitamin D (25(OH)D), glycaemic as well as adiposity indicators were evaluated before and after the intervention. VDR-Cdx-2 genotypes in extended number of T2D subjects in the FD group (n 60) were determined as AA, GA and GG. After 12 weeks, in FD compared with PD, serum 25(OH)D increased (+35·4 v. -4·8 nmol/l; P<0·001) and mean changes of waist circumference (WC; -1·3 v. +1·6 cm; P=0·02), body fat mass (FM; -1·9 v. +0·60 %; P=0·008), truncal fat (TF; -1·1 v. 0·13 %; P=0·003) and visceral adipose tissue (-0·80 v. +0·37 AU; P<0·001) decreased significantly. Circulating 25(OH)D was raised only in the AA group (34·8 nmo/l in AA group v. -6·4 nmol/l in AG and -1·6 nmol/l in GG groups; P<0·001), which was accompanied by a significant decrease in changes of WC (P=0·004), FM% (P=0·01) and TF% (P<0·001) in the AA genotype. Daily intake of vitamin D-FD for 12 weeks improved the central obesity indices in T2D subjects, and the improvement was more pronounced in the carriers of the AA genotype of VDR-Cdx-2.
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Garatachea N, Fuku N, He ZH, Tian Y, Arai Y, Abe Y, Murakami H, Miyachi M, Yvert T, Venturini L, Santiago C, Santos-Lozano A, Rodríguez G, Ricevuti G, Pareja-Galeano H, Sanchis-Gomar F, Emanuele E, Hirose N, Lucia A. PTK2 rs7460 and rs7843014 polymorphisms and exceptional longevity: a functional replication study. Rejuvenation Res 2015; 17:430-8. [PMID: 24930376 DOI: 10.1089/rej.2014.1570] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Focal adhesion is critical for cell survival. The focal adhesion kinase (FAK, or PTK2) is an important component of the human interactome and thus is a potential longevity-related protein. Here we studied the association between two PTK2 gene single-nucleotide polymorphisms (SNPs) (rs7843014, rs7460) and exceptional longevity (EL). In addition to gaining insight into their functionality by determining luciferase gene reporter activity, we studied the genotype/allele frequency of these two SNPs among three different cohorts: (1) Spanish centenarians (n=175, 100-111 years, 144 women) and healthy controls (n=355, 20-50 years, 284 women); (2) Italian centenarians (n=79, 100-104 years, 40 women) and controls (n=316, 29-50 years, 156 women); and (3) Japanese centenarians (n=742, 100-116 years, 623 women) and healthy controls (n=499, 23-59 years, 356 women). Both SNPs had functional significance, with the A allele up-regulating luciferase activity compared to the other allele (rs7460 T allele and rs7843014 C allele, respectively). The A allele of both SNPs was negatively associated with EL in the Spanish cohort (rs7460, odds ratio [OR] adjusted by sex=0.40, 95% confidence intervals [CI] 0.3, 0.6, p<0.001); rs7843014, OR=0.37, 95% CI 0.3, 0.5, p<0.001). The OR of being a centenarian if having the rs7460-TT genotype was 6.68 (95% CI 4.1, 10.8, p<0.001). The rs7843014 CC genotype was also positively associated with EL (OR=7.58, 95% CI 4.6, 12.3, p<0.001]. No association was, however, found for the Italian or Japanese cohorts. Thus, two genotypes of the FAK gene, rs7460 TT and rs7843014 CC, are possibly associated with lower gene expression and might favor the likelihood of reaching EL in the Spanish population. Further research is needed to unveil the mechanisms by which FAK expression could perhaps influence the rate of aging.
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Affiliation(s)
- Nuria Garatachea
- 1 Faculty of Health and Sport Science, University of Zaragoza , Huesca, Spain
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PNPLA3 Gene Polymorphism Is Associated With Predisposition to and Severity of Alcoholic Liver Disease. Am J Gastroenterol 2015; 110:846-56. [PMID: 25964223 DOI: 10.1038/ajg.2015.137] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 04/01/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The genetic polymorphism with an isoleucine-to-methionine substitution at position 148 (rs738409 C>G) in the patatin-like phospholipase domain protein 3 (PNPLA3) gene confers risk of steatosis. PNPLA3 polymorphism is shown to be associated with alcoholic liver disease (ALD). We performed a systematic review and meta-analysis to examine association of this genetic polymorphism with ALD spectrum and its severity. METHODS Medline, Embase, and Cochrane Library were searched for studies on association of PNPLA3 polymorphism and ALD spectrum: alcoholic fatty liver (AFL), alcoholic liver injury (ALI), alcoholic cirrhosis (AC), and hepatocellular carcinoma (HCC). Pooled data are reported as odds ratio (OR) with 95% confidence interval. Heterogeneity was assessed using the I(2) statistics and publication bias using Egger's test and Begg and Mazumdar's test. Individual participant data obtained from five studies were used for subgroup analyses. RESULTS Among 10 studies included in this pooled analysis, compared with controls, OR for rs738409 CG and GG among ALI patients was 1.45 (1.24-1.69) and 2.22 (1.50-3.28), respectively, compared with CC. Respective OR among AC patients was 2.09 (1.79-2.44) and 3.37 (2.49-4.58) and among AC patients with HCC was 2.87 (1.61-5.10) and 12.41 (6.99-22.03). Data for AFL were inconsistent. Among ALD patients, OR of CG and GG genotypes was 2.62 (1.73-3.97) and 8.45 (2.52-28.37), respectively, for AC compared with fatty liver (FL) patients. Similar OR for AC compared with ALI was 1.98 (1.24-3.17) and 3.86 (1.18-12.60). The OR for CG and GG genotypes among AC patients for HCC occurrence was 1.43 (0.76-2.72) and 2.81 (1.57-5.01), respectively. Individual participant data analysis showed age to predispose to AC among ALI patients. CONCLUSIONS PNPLA3 genetic polymorphism (rs738409 C>G) is associated with increased risk for the entire spectrum of ALD among drinkers including ALI, AC, and HCC. Studies are needed to clarify association of PNPLA3 polymorphism and steatosis in alcoholics. PNPLA3 gene may potentially be a therapeutic target in ALD.
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Fuku N, He ZH, Sanchis-Gomar F, Pareja-Galeano H, Tian Y, Arai Y, Abe Y, Murakami H, Miyachi M, Zempo H, Naito H, Yvert T, Verde Z, Venturini L, Fiuza-Luces C, Santos-Lozano A, Rodriguez-Romo G, Ricevuti G, Hirose N, Emanuele E, Garatachea N, Lucia A. Exceptional longevity and muscle and fitness related genotypes: a functional in vitro analysis and case-control association replication study with SNPs THRH rs7832552, IL6 rs1800795, and ACSL1 rs6552828. Front Aging Neurosci 2015; 7:59. [PMID: 25999849 PMCID: PMC4422078 DOI: 10.3389/fnagi.2015.00059] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/07/2015] [Indexed: 01/05/2023] Open
Abstract
There are several gene variants that are candidates to influence functional capacity in long-lived individuals. As such, their potential association with exceptional longevity (EL, i.e., reaching 100+ years) deserves analysis. Among them are rs7832552 in the thyrotropin-releasing hormone receptor (TRHR) gene, rs1800795 in the interleukin-6 (IL6) gene and rs6552828 in the coenzyme A synthetase long-chain 1 (ACSL1) gene. To gain insight into their functionality (which is yet unknown), here we determined for the first time luciferase gene reporter activity at the muscle tissue level in rs7832552 and rs6552828. We then compared allele/genotype frequencies of the 3 abovementioned variants among centenarians [n = 138, age range 100–111 years (114 women)] and healthy controls [n = 334, 20–50 years (141 women)] of the same ethnic and geographic origin (Spain). We also studied healthy centenarians [n = 79, 100–104 years (40 women)] and controls [n = 316, 27–81 years (156 women)] from Italy, and centenarians [n = 742, 100–116 years (623 women)] and healthy controls [n = 499, 23–59 years (356 women)] from Japan. The THRH rs7832552 T-allele and ACSL1 rs6552828 A-allele up-regulated luciferase activity compared to the C and G-allele, respectively (P = 0.001). Yet we found no significant association of EL with rs7832552, rs1800795 or rs6552828 in any of the 3 cohorts. Further research is needed with larger cohorts of centenarians of different origin as well as with younger old people.
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Affiliation(s)
- Noriyuki Fuku
- Graduate School of Health and Sports Science, Juntendo University Chiba, Japan
| | - Zi-Hong He
- Biology Centre, China Institute of Sport Science Beijing, China
| | | | - Helios Pareja-Galeano
- Research Institute of Hospital 12 de Octubre ("i+12") Madrid, Spain ; School of Doctorate Studies and Research, European University of Madrid Madrid, Spain
| | - Ye Tian
- Biology Centre, China Institute of Sport Science Beijing, China
| | - Yasumichi Arai
- Center for Supercentenarian Study, Keio University School of Medicine Tokyo, Japan
| | - Yukiko Abe
- Center for Supercentenarian Study, Keio University School of Medicine Tokyo, Japan
| | - Haruka Murakami
- Department of Health Promotion and Exercise, National Institute of Health and Nutrition Tokyo, Japan
| | - Motohiko Miyachi
- Department of Health Promotion and Exercise, National Institute of Health and Nutrition Tokyo, Japan
| | - Hirofumi Zempo
- Graduate School of Health and Sports Science, Juntendo University Chiba, Japan
| | - Hisashi Naito
- Graduate School of Health and Sports Science, Juntendo University Chiba, Japan
| | - Thomas Yvert
- School of Doctorate Studies and Research, European University of Madrid Madrid, Spain
| | - Zoraida Verde
- School of Doctorate Studies and Research, European University of Madrid Madrid, Spain
| | | | - Carmen Fiuza-Luces
- School of Doctorate Studies and Research, European University of Madrid Madrid, Spain
| | | | | | | | - Nobuyoshi Hirose
- Center for Supercentenarian Study, Keio University School of Medicine Tokyo, Japan
| | - Enzo Emanuele
- Department of Health Sciences, University of Pavia Pavia, Italy
| | - Nuria Garatachea
- School of Doctorate Studies and Research, European University of Madrid Madrid, Spain ; Department of Physiotherapy and Nursing, Faculty of Health and Sport Science, University of Zaragoza Huesca, Spain
| | - Alejandro Lucia
- Research Institute of Hospital 12 de Octubre ("i+12") Madrid, Spain ; School of Doctorate Studies and Research, European University of Madrid Madrid, Spain
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Hassanin OM. Hardy–Weinberg disequilibrium and association study of insertion/deletion polymorphism of ACE gene and Alzheimer’s disease in Egyptian patients. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2015. [DOI: 10.1016/j.ejmhg.2014.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Permoda-Osip A, Dmitrzak-Weglarz M, Hauser J, Rybakowski JK. Are genes connected with homocysteine metabolism associated with bipolar disorder? Neuropsychobiology 2014; 69:107-11. [PMID: 24577139 DOI: 10.1159/000358091] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 12/16/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND Increased levels of homocysteine have been observed in various psychiatric disorders, among them in schizophrenia, depression and bipolar mood disorder. Of the genes connected with homocysteine metabolism, some studies have found an association between polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene and bipolar disorder. The aim of this study was to investigate a possible association between 5 polymorphisms of 4 genes coding enzymes of homocysteine metabolism and bipolar disorder. METHOD A total of 120 patients with bipolar disorder (24 male, 96 female) and 167 subjects from the general population (81 male, 86 female) were included in the study. Genotyping was performed for the C677T (rs1801133) and A1298C (rs1801131) polymorphisms of the MTHFR gene, for the T833C polymorphism (rs5742905) of the cystathionine-β-synthase (CBS) gene, for the A2756G polymorphism (rs1805087) of the homocysteine methyltransferase gene, and for the A66G polymorphism (rs1801394) of the methionine synthase reductase (MTRR) gene. RESULTS An association with bipolar disorder was found for the T833C polymorphism (rs5742905) of the CBS gene. However, in the patient sample, the genotypes of this polymorphism were not in Hardy-Weinberg equilibrium. No relationship to bipolar disorder was obtained for the remaining polymorphisms studied. CONCLUSIONS These results are the first suggesting a possible association between T833C polymorphism (rs5742905) of the CBS gene and bipolar disorder. We were unable to confirm an association between bipolar disorder and C677T polymorphism (rs1801133) of the MTHFR gene, as suggested in some previous studies.
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Bastos JV, Côrtes MIS, Silva JFC, Goulart EMA, Colosimo EA, Gomez RS, Dutra WO. A study of the interleukin-1 gene cluster polymorphisms and inflammatory external root resorption in replanted permanent teeth. Int Endod J 2014; 48:878-87. [PMID: 25266756 DOI: 10.1111/iej.12384] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 09/24/2014] [Indexed: 11/30/2022]
Abstract
AIM To investigate whether single nucleotide polymorphisms (SNPs) within the interleukin-1 gene cluster (IL1) are associated with the occurrence and severity of inflammatory external root resorption (IERR) after replantation of avulsed permanent teeth. METHODOLOGY Indexes of IERR were radiographically assessed in 182 mature replanted permanent teeth from 146 patients at the onset of endodontic therapy. DNA was extracted from buccal mucosa cells and genotyped using TaqMan probes-based assays for the SNPs IL1A -889C/T (rs 180058), IL1B +3954C/T (rs1143634) and IL1RN +2018C/T (rs419598). Teeth were grouped into two categories: IERR absent to mild (indexes ≤ 4) and moderate to severe IERR (indexes > 4). Genetic variations in the IL1 gene cluster were tested for their effect on the occurrence and extension of IERR using the GEE model (generalized estimation equation). Patient's age at the moment of injury, timing of pulpectomy, extra-alveolar period and storage condition of the avulsed teeth was included as possible confounders. RESULTS No association was found between SNPs IL1A -889C/T, IL1B +3954C/T (rs1143634) and IL1RN +2018C/T (rs419598) and IERR indexes. Timing of pulpectomy (OR 3.5 IC 95% 2.0-6.2 P < 0.001) and patient's age at the moment of trauma (OR 0.29 IC 95% 0.12-0.67 P = 0.004) significantly affected the risk of developing severe IERR. CONCLUSIONS While timing of pulpectomy and patient's age at the moment of trauma were confirmed as important risk factors, SNPs within the IL1 gene cluster did not affect the susceptibility for IERR after replantation of permanent teeth.
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Affiliation(s)
- J V Bastos
- Dental Trauma Programme, Department of Restorative Dentistry, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - M I S Côrtes
- Dental Trauma Programme, Department of Restorative Dentistry, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - J F C Silva
- Faculty of Health and Biological Sciences, Newton Paiva University Center, Belo Horizonte, MG, Brazil
| | - E M A Goulart
- Department of Pediatrics, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - E A Colosimo
- Department of Statistics, Institute of Exact Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - R S Gomez
- Department of Oral Surgery and Pathology, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - W O Dutra
- Laboratory of Cell-cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Differential susceptibility to effects of maternal sensitivity? A study of candidate plasticity genes. Dev Psychopathol 2014; 27:725-46. [DOI: 10.1017/s0954579414000844] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
AbstractHere we tested whether there was genetic moderation of effects of early maternal sensitivity on social–emotional and cognitive–linguistic development from early childhood onward and whether any detected Gene × Environment interaction effects proved consistent with differential-susceptibility or diathesis–stress models of Person × Environment interaction (N= 695). Two new approaches for evaluating models were employed with 12 candidate genes. Whereas maternal sensitivity proved to be a consistent predictor of child functioning across the primary-school years, candidate genes did not show many main effects, nor did they tend to interact with maternal sensitivity/insensitivity. These findings suggest that the developmental benefits of early sensitive mothering and the costs of insensitive mothering look more similar than different across genetically different children in the current sample. Although acknowledgement of this result is important, it is equally important that the generally null Gene × Environment results reported here not be overgeneralized to other samples, other predictors, other outcomes, and other candidate genes.
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Berry D, Deater-Deckard K, McCartney K, Wang Z, Petrill SA. Gene-environment interaction between dopamine receptor D4 7-repeat polymorphism and early maternal sensitivity predicts inattention trajectories across middle childhood. Dev Psychopathol 2013; 25:291-306. [PMID: 23627945 PMCID: PMC8182928 DOI: 10.1017/s095457941200106x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Evidence suggests that the 7-repeat variant of a 48 base pair variable number tandem repeat polymorphism in the dopamine receptor D4 (DRD4) gene may be associated with the development of attention problems. A parallel literature suggests that genes linked to dopaminergic functioning may be associated with differential sensitivity to context, such that the direction of the genetic effect is hypothesized to vary across environmental experience. Guided by these literatures, we used data from the NICHD Study of Early Child Care and Youth Development to consider (a) whether individual differences in children's inattention problems across middle childhood are predicted by gene-environment interactions between the DRD4 gene 7-repeat polymorphism and children's experiences of maternal sensitivity across infancy and early childhood and (b) the degree to which such interactions are consistent with the differential-sensitivity model. Largely consistent with the hypothesized model, gene-environment interactions indicated that, in the context of insensitive early maternal care, the DRD4 7-repeat polymorphism was associated with higher levels of inattention. Although somewhat less consistently, there was also evidence that, in the context of highly sensitive care, the 7-repeat polymorphism was associated with lower levels of inattention. Overall, the magnitude of the absolute genetic effect increased over time, as children's inattention trajectories diverged.
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Affiliation(s)
- Daniel Berry
- University of Illinois, Urbana-Champaign, 61820, USA.
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Meyer NJ, Feng R, Li M, Zhao Y, Sheu CC, Tejera P, Gallop R, Bellamy S, Rushefski M, Lanken PN, Aplenc R, O'Keefe GE, Wurfel MM, Christiani DC, Christie JD. IL1RN coding variant is associated with lower risk of acute respiratory distress syndrome and increased plasma IL-1 receptor antagonist. Am J Respir Crit Care Med 2013; 187:950-9. [PMID: 23449693 PMCID: PMC3707367 DOI: 10.1164/rccm.201208-1501oc] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 03/01/2013] [Indexed: 12/21/2022] Open
Abstract
RATIONALE Acute respiratory distress syndrome (ARDS) behaves as a complex genetic trait, yet knowledge of genetic susceptibility factors remains incomplete. OBJECTIVES To identify genetic risk variants for ARDS using large scale genotyping. METHODS A multistage genetic association study was conducted of three critically ill populations phenotyped for ARDS. Stage I, a trauma cohort study (n = 224), was genotyped with a 50K gene-centric single-nucleotide polymorphism (SNP) array. We tested SNPs associated with ARDS at P < 5 × 10(-4) for replication in stage II, a trauma case-control population (n = 778). SNPs replicating their association in stage II (P < 0.005) were tested in a stage III nested case-control population of mixed subjects in the intensive care unit (n = 2,063). Logistic regression was used to adjust for potential clinical confounders. We performed ELISA to test for an association between ARDS-associated genotype and plasma protein levels. MEASUREMENTS AND MAIN RESULTS A total of 12 SNPs met the stage I threshold for an association with ARDS. rs315952 in the IL1RN gene encoding IL-1 receptor antagonist (IL1RA) replicated its association with reduced ARDS risk in stages II (P < 0.004) and III (P < 0.02), and was robust to clinical adjustment (combined odds ratio = 0.81; P = 4.2 × 10(-5)). Plasma IL1RA level was associated with rs315952C in a subset of critically ill subjects. The effect of rs315952 was independent from the tandem repeat variant in IL1RN. CONCLUSIONS The IL1RN SNP rs315952C is associated with decreased risk of ARDS in three populations with heterogeneous ARDS risk factors, and with increased plasma IL1RA response. IL1RA may attenuate ARDS risk.
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Affiliation(s)
- Nuala J Meyer
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Qian M, Shao Y. A likelihood ratio test for goodness-of-fit of recessive and dominant models for case-control studies. CAN J STAT 2013. [DOI: 10.1002/cjs.11171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Izbicki R, Fossaluza V, Hounie AG, Nakano EY, de Bragança Pereira CA. Testing allele homogeneity: the problem of nested hypotheses. BMC Genet 2012; 13:103. [PMID: 23176636 PMCID: PMC3770452 DOI: 10.1186/1471-2156-13-103] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/16/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The evaluation of associations between genotypes and diseases in a case-control framework plays an important role in genetic epidemiology. This paper focuses on the evaluation of the homogeneity of both genotypic and allelic frequencies. The traditional test that is used to check allelic homogeneity is known to be valid only under Hardy-Weinberg equilibrium, a property that may not hold in practice. RESULTS We first describe the flaws of the traditional (chi-squared) tests for both allelic and genotypic homogeneity. Besides the known problem of the allelic procedure, we show that whenever these tests are used, an incoherence may arise: sometimes the genotypic homogeneity hypothesis is not rejected, but the allelic hypothesis is. As we argue, this is logically impossible. Some methods that were recently proposed implicitly rely on the idea that this does not happen. In an attempt to correct this incoherence, we describe an alternative frequentist approach that is appropriate even when Hardy-Weinberg equilibrium does not hold. It is then shown that the problem remains and is intrinsic of frequentist procedures. Finally, we introduce the Full Bayesian Significance Test to test both hypotheses and prove that the incoherence cannot happen with these new tests. To illustrate this, all five tests are applied to real and simulated datasets. Using the celebrated power analysis, we show that the Bayesian method is comparable to the frequentist one and has the advantage of being coherent. CONCLUSIONS Contrary to more traditional approaches, the Full Bayesian Significance Test for association studies provides a simple, coherent and powerful tool for detecting associations.
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Affiliation(s)
- Rafael Izbicki
- Department of Statistics, Carnegie Mellon University, Pittsburgh, USA.
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Li Y, Li Z, Graubard BI. Testing for Hardy Weinberg Equilibrium in national household surveys that collect family-based genetic data. Ann Hum Genet 2011; 75:732-41. [PMID: 21972963 DOI: 10.1111/j.1469-1809.2011.00680.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In population-based household surveys, for example, the National Health and Nutrition Examination Survey (NHANES), blood-related individuals are often sampled from the same household. Therefore, genetic data collected from national household surveys are often correlated due to two levels of clustering (correlation) with one induced by the multistage geographical cluster sampling, and the other induced by biological inheritance among multiple participants within the same sampled household. In this paper, we develop efficient statistical methods that consider the weighting effect induced by the differential selection probabilities in complex sample designs, as well as the clustering (correlation) effects described above. We examine and compare the magnitude of each level of clustering effects under different scenarios and identify the scenario under which the clustering effect induced by one level dominates the other. The proposed method is evaluated via Monte Carlo simulation studies and illustrated using the Hispanic Health and Nutrition Survey (HHANES) with simulated genotype data.
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Affiliation(s)
- Yan Li
- Department of Mathematics, University of Texas at Arlington, TX 76019, USA.
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Souren NY, Zeegers MP. Is Hardy-Weinberg on its retreat? J Clin Epidemiol 2011; 64:819-20. [DOI: 10.1016/j.jclinepi.2011.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Dennis J, Hawken S, Krewski D, Birkett N, Gheorghe M, Frei J, McKeown-Eyssen G, Little J. Bias in the case-only design applied to studies of gene-environment and gene-gene interaction: a systematic review and meta-analysis. Int J Epidemiol 2011; 40:1329-41. [PMID: 21729879 DOI: 10.1093/ije/dyr088] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The case-only study, proposed as a design specifically for assessing departure from multiplicative gene-environment and gene-gene interactions, is of considerable potential value but there are concerns about its validity. The objective of this study was to evaluate the extent and sources of bias in the case-only design by means of a systematic review and meta-regression analysis. METHODS The MEDLINE, CINAHL, EMBASE and PUBMED databases were searched through to 7 October 2009. Studies that assessed bias in the case-only design applied to the study of gene-environment and gene-gene interaction were identified. Qualitative comments on the sources and extent of bias were extracted. A meta-regression analysis of the ratio (IOR(CC)/IOR(CO)) of the case-control (IOR(CC)) and case-only (IOR(CO)) interaction odds ratios was conducted based on studies in which both methods were applied to the same data set. RESULTS The search yielded 365 unique articles of which 38 met the inclusion criteria. Potential sources of bias in the case-only design included non-independence of genotype and exposure in the source population. Meta-regression analysis, based on 24 evaluations, produced a mean IOR(CC)/IOR(CO) of 1.06 [95% confidence interval (95% CI) 0.93-1.22], suggesting that bias in case-only designs is not common in practice. The I(2) statistic indicated that 23.9% (95% uncertainty interval 0-53.9%) of the observed variation was due to heterogeneity between studies, which was not explained by any methodological characteristics of the included studies. CONCLUSION As understanding of the relationships between genes and environmental exposures in the population improves, the case-only design may prove to be of considerable value.
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Affiliation(s)
- Jessica Dennis
- Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada.
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Abstract
Kashin-Beck disease (KBD) is a chronic endemic osteoarthropathy, which mainly occurs in West and Northeast China. Epidemiological studies suggest that Se deficiency is an important environmental factor for the incidence of KBD. Glutathione peroxidase 4 (GPx4) belongs to the glutathione peroxidase family, which is crucial for optimal antioxidant defences. Our purpose is to investigate the putative association between GPx4 polymorphisms and the risk of KBD. Restriction fragment length polymorphism-PCR was used to detect two SNP (rs713041, rs4807542) in 219 cases and 194 controls in Han Chinese subjects, and quantitative analysis for the GPx4 mRNA level was performed by the real-time PCR method. The results revealed that linkage disequilibrium existed in the two SNP. A significant difference was observed in the haplotype A-T (P = 0·0066) of GPx4, which was obviously lower in the KBD cases (0·006 v. 0·032 %). Correlation analysis based on a single locus showed no association between each SNP and KBD risk. Furthermore, the GPx4 mRNA level was dramatically lower in the blood of KBD patients. Overall, our finding indicated GPx4 polymorphisms and decreased mRNA level may be related to the development of KBD in the Chinese population, suggesting GPx4 as a possible candidate susceptibility gene for KBD.
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Zhong N, Zhang R, Qiu C, Yan H, Valenzuela RK, Zhang H, Kang W, Lu S, Guo T, Ma J. A novel replicated association between FXYD6 gene and schizophrenia. Biochem Biophys Res Commun 2011; 405:118-21. [DOI: 10.1016/j.bbrc.2011.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 01/02/2011] [Indexed: 12/27/2022]
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Wijsman EM, Pankratz ND, Choi Y, Rothstein JH, Faber KM, Cheng R, Lee JH, Bird TD, Bennett DA, Diaz-Arrastia R, Goate AM, Farlow M, Ghetti B, Sweet RA, Foroud TM, Mayeux R. Genome-wide association of familial late-onset Alzheimer's disease replicates BIN1 and CLU and nominates CUGBP2 in interaction with APOE. PLoS Genet 2011; 7:e1001308. [PMID: 21379329 PMCID: PMC3040659 DOI: 10.1371/journal.pgen.1001308] [Citation(s) in RCA: 189] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 01/12/2011] [Indexed: 12/13/2022] Open
Abstract
Late-onset Alzheimer's disease (LOAD) is the most common form of dementia in the elderly. The National Institute of Aging-Late Onset Alzheimer's Disease Family Study and the National Cell Repository for Alzheimer's Disease conducted a joint genome-wide association study (GWAS) of multiplex LOAD families (3,839 affected and unaffected individuals from 992 families plus additional unrelated neurologically evaluated normal subjects) using the 610 IlluminaQuad panel. This cohort represents the largest family-based GWAS of LOAD to date, with analyses limited here to the European-American subjects. SNPs near APOE gave highly significant results (e.g., rs2075650, p = 3.2×10(-81)), but no other genome-wide significant evidence for association was obtained in the full sample. Analyses that stratified on APOE genotypes identified SNPs on chromosome 10p14 in CUGBP2 with genome-wide significant evidence for association within APOE ε4 homozygotes (e.g., rs201119, p = 1.5×10(-8)). Association in this gene was replicated in an independent sample consisting of three cohorts. There was evidence of association for recently-reported LOAD risk loci, including BIN1 (rs7561528, p = 0.009 with, and p = 0.03 without, APOE adjustment) and CLU (rs11136000, p = 0.023 with, and p = 0.008 without, APOE adjustment), with weaker support for CR1. However, our results provide strong evidence that association with PICALM (rs3851179, p = 0.69 with, and p = 0.039 without, APOE adjustment) and EXOC3L2 is affected by correlation with APOE, and thus may represent spurious association. Our results indicate that genetic structure coupled with ascertainment bias resulting from the strong APOE association affect genome-wide results and interpretation of some recently reported associations. We show that a locus such as APOE, with large effects and strong association with disease, can lead to samples that require appropriate adjustment for this locus to avoid both false positive and false negative evidence of association. We suggest that similar adjustments may also be needed for many other large multi-site studies.
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Affiliation(s)
- Ellen M. Wijsman
- Division of Medical Genetics, University of Washington, Seattle, Washington, United States of America
- Department of Biostatistics, University of Washington, Seattle, Washington, United States of America
| | - Nathan D. Pankratz
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Yoonha Choi
- Department of Biostatistics, University of Washington, Seattle, Washington, United States of America
| | - Joseph H. Rothstein
- Division of Medical Genetics, University of Washington, Seattle, Washington, United States of America
| | - Kelley M. Faber
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Rong Cheng
- The Gertrude H. Sergievsky Center, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, United States of America
| | - Joseph H. Lee
- The Gertrude H. Sergievsky Center, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, United States of America
| | - Thomas D. Bird
- Division of Medical Genetics, University of Washington, Seattle, Washington, United States of America
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle Division, Seattle, Washington, United States of America
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - David A. Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Ramon Diaz-Arrastia
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Alison M. Goate
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Martin Farlow
- Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Bernardino Ghetti
- Department of Pathology, Division of Neuropathology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Robert A. Sweet
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Tatiana M. Foroud
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Richard Mayeux
- The Gertrude H. Sergievsky Center, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, New York, United States of America
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Zhang R, Zhong NN, Liu XG, Yan H, Qiu C, Han Y, Wang W, Hou WK, Liu Y, Gao CG, Guo TW, Lu SM, Deng HW, Ma J. Is the EFNB2 locus associated with schizophrenia? Single nucleotide polymorphisms and haplotypes analysis. Psychiatry Res 2010; 180:5-9. [PMID: 20483485 DOI: 10.1016/j.psychres.2010.04.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 04/10/2010] [Accepted: 04/25/2010] [Indexed: 12/18/2022]
Abstract
Recently, evidence of linkage of schizophrenia to chromosome 13q22-q34 has been demonstrated in multiple studies. Based on structure and function, EFNB2 may be considered as a compelling candidate gene for schizophrenia on chromosome 13q33. We genotyped three single-nucleotide polymorphisms (SNPs: rs9520087, rs11069646, and rs8000078) in this region in 846 Han Chinese subjects (477 cases and 369 controls). Significant association between an allele of marker rs9520087 and schizophrenia was found. Furthermore, since no LD was observed in the three SNPs linkage disequilibrium estimation, all three SNPs were used in multiple SNPs haplotype analysis, and a strongly significant difference was found for the common haplotype TTC. Overall our findings indicate that EFNB2 gene may be a candidate susceptibility gene for schizophrenia in the Han Chinese population, and also provide further support for the potential importance of the NMDA receptor pathway in the etiology of schizophrenia.
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Affiliation(s)
- Rui Zhang
- Department of Genetics and Molecular Biology, and First Affliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, PR China
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Graffelman J. The number of markers in the HapMap project: some notes on chi-square and exact tests for Hardy-Weinberg equilibrium. Am J Hum Genet 2010; 86:813-8; author reply 818-9. [PMID: 20466092 DOI: 10.1016/j.ajhg.2009.11.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 11/20/2009] [Accepted: 11/20/2009] [Indexed: 12/21/2022] Open
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Abstract
Genome-wide association studies of discrete traits generally use simple methods of analysis based on chi(2) tests for contingency tables or logistic regression, at least for an initial scan of the entire genome. Nevertheless, more power might be obtained by using various methods that analyze multiple markers in combination. Methods based on sliding windows, wavelets, Bayesian shrinkage, or penalized likelihood methods, among others, were explored by various participants of Genetic Analysis Workshop 16 Group 1 to combine information across multiple markers within a region, while others used Bayesian variable selection methods for genome-wide multivariate analyses of all markers simultaneously. Imputation can be used to fill in missing markers on individual subjects within a study or in a meta-analysis of studies using different panels. Although multiple imputation theoretically should give more robust tests of association, one participant contribution found little difference between results of single and multiple imputation. Careful control of population stratification is essential, and two contributions found that previously reported associations with two genes disappeared after more precise control. Other issues considered by this group included subgroup analysis, gene-gene interactions, and the use of biomarkers.
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Affiliation(s)
- Duncan C Thomas
- Department of Preventive Medicine, University of Southern California, Los Angeles, California 90089-9011, USA.
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Wang J, Shete S. Using both cases and controls for testing hardy-weinberg proportions in a genetic association study. Hum Hered 2010; 69:212-8. [PMID: 20203526 DOI: 10.1159/000289597] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Accepted: 01/04/2010] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Assessment of the Hardy-Weinberg proportion (HWP) in controls has been widely used as a quality control measure in case-control association studies. However, when the disease being studied is common, controls might not represent the general population, which could result in inaccurate HWP test results. Such results could lead investigators to discard important single-nucleotide polymorphisms (SNPs) that could potentially be causal. In this paper, we showed the inappropriateness of the HWP test in controls and proposed a mixture HWP (mHWP) exact test using a mixture sample that mimics the general population. METHODS The mHWP exact test estimates HWP in a mixture sample that is a combination of both cases and controls proportional to the prevalence of disease. We implemented a re-sampling procedure to construct mixture samples and then obtained the empirical p value of HWP in the general population. Simulation studies were performed to investigate the performance of the proposed mHWP exact test. The method was also applied to a genetic association study of obesity. RESULTS The results showed that the mHWP exact test is more likely than either the traditional HWP method in controls or the likelihood-based approach to keep causal SNPs for further analysis when the disease is more common. CONCLUSION The mHWP exact test using a mixture sample is a better HWP test for case-control genetic association studies than the traditional HWP in controls or the likelihood-based approach, and it will improve our ability to keep causal SNPs in the case-control genetic association studies.
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Affiliation(s)
- Jian Wang
- Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
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Little J, Higgins JPT, Ioannidis JPA, Moher D, Gagnon F, von Elm E, Khoury MJ, Cohen B, Davey-Smith G, Grimshaw J, Scheet P, Gwinn M, Williamson RE, Zou GY, Hutchings K, Johnson CY, Tait V, Wiens M, Golding J, van Duijn C, McLaughlin J, Paterson A, Wells G, Fortier I, Freedman M, Zecevic M, King R, Infante-Rivard C, Stewart A, Birkett N. STrengthening the REporting of Genetic Association Studies (STREGA)--an extension of the STROBE statement. Genet Epidemiol 2010; 33:581-98. [PMID: 19278015 DOI: 10.1002/gepi.20410] [Citation(s) in RCA: 185] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Making sense of rapidly evolving evidence on genetic associations is crucial to making genuine advances in human genomics and the eventual integration of this information in the practice of medicine and public health. Assessment of the strengths and weaknesses of this evidence, and hence the ability to synthesize it, has been limited by inadequate reporting of results. The STrengthening the REporting of Genetic Association studies (STREGA) initiative builds on the STrengthening the Reporting of OBservational Studies in Epidemiology (STROBE) Statement and provides additions to 12 of the 22 items on the STROBE checklist. The additions concern population stratification, genotyping errors, modelling haplotype variation, Hardy-Weinberg equilibrium, replication, selection of participants, rationale for choice of genes and variants, treatment effects in studying quantitative traits, statistical methods, relatedness, reporting of descriptive and outcome data, and the volume of data issues that are important to consider in genetic association studies. The STREGA recommendations do not prescribe or dictate how a genetic association study should be designed but seek to enhance the transparency of its reporting, regardless of choices made during design, conduct, or analysis.
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Affiliation(s)
- Julian Little
- Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
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Lin E, Chen PS, Chang HH, Gean PW, Tsai HC, Yang YK, Lu RB. Interaction of serotonin-related genes affects short-term antidepressant response in major depressive disorder. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:1167-72. [PMID: 19560507 DOI: 10.1016/j.pnpbp.2009.06.015] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 06/16/2009] [Accepted: 06/17/2009] [Indexed: 11/28/2022]
Abstract
BACKGROUND Four serotonin-related genes including guanine nucleotide binding protein beta polypeptide 3 (GNB3), 5-hydroxytryptamine receptor 1A (HTR1A; serotonin receptor 1A), 5-hydroxytryptamine receptor 2A (HTR2A; serotonin receptor 2A), and solute carrier family 6 member 4 (SLC6A4; serotonin neurotransmitter transporter) have been suggested to be candidate genes for influencing antidepressant treatment outcome. The aim of this study was to explore whether interaction among these genes could contribute to the pharmacogenomics of short-term antidepressant response in a Taiwanese population with major depressive disorder (MDD). METHODS Included in this study were 101 MDD patients who were treated with antidepressants, 35 of whom were rapid responders and 66 non-responders after 2weeks of treatment. We genotyped four single nucleotide polymorphisms (SNPs), including GNB3 rs5443 (C825T), HTR1A rs6295 (C-1019G), HTR2A rs6311 (T102C), and SLC6A4 rs25533, and employed the generalized multifactor dimensionality reduction (GMDR) method to investigate gene-gene interactions. RESULTS Single-locus analyses showed the GNB3 rs5443 polymorphism to be associated with short-term antidepressant treatment outcome (P-value=0.029). We did not correct for multiple testing in these multiple exploratory analyses. Finally, the GMDR approach identified a significant gene-gene interaction (P-value=0.025) involving GNB3 and HTR2A, as well as a significant 3-locus model (P-value=0.015) among GNB3, HTR2A, and SLC6A4. CONCLUSIONS These results support the hypothesis that GNB3, HTR2A, and SLC6A4 may play a role in the outcome of short-term antidepressant treatment for MDD in an interactive manner. Future research with independent replication using large sample sizes is needed to confirm the functions of the candidate genes identified in this study as being involved in short-term antidepressant treatment response.
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Affiliation(s)
- Eugene Lin
- Vita Genomics, Inc, Wugu Shiang, Taipei, Taiwan
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Abstract
Exact conditional tests are often required to evaluate statistically whether a sample of diploids comes from a population with Hardy-Weinberg proportions or to confirm the accuracy of genotype assignments. This requirement is especially common when the sample includes multiple alleles and sparse data, thus rendering asymptotic methods, such as the common chi(2)-test, unreliable. Such an exact test can be performed using the likelihood ratio as its test statistic rather than the more commonly used probability test. Conceptual advantages in using the likelihood ratio are discussed. A substantially improved algorithm is described to permit the performance of a full-enumeration exact test on sample sizes that are too large for previous methods. An improved Monte Carlo algorithm is also proposed for samples that preclude full enumeration. These algorithms are about two orders of magnitude faster than those currently in use. Finally, methods are derived to compute the number of possible samples with a given set of allele counts, a useful quantity for evaluating the feasibility of the full enumeration procedure. Software implementing these methods, ExactoHW, is provided.
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Yu C, Zhang S, Zhou C, Sile S. A likelihood ratio test of population Hardy-Weinberg equilibrium for case-control studies. Genet Epidemiol 2009; 33:275-80. [PMID: 19025784 DOI: 10.1002/gepi.20381] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Testing Hardy-Weinberg equilibrium (HWE) in the control group is commonly used to detect genotyping errors in genetic association studies. We propose a likelihood ratio test for testing HWE in the study population using both case and control samples. This test incorporates underlying association models. Another feature is that, when we infer the disease-genotype association, we explicitly incorporate HWE or a possible departure from Hardy-Weinberg equilibrium (DHWE) into the model. Our unified framework enables us to infer the disease-genotype association when a detected DHWE needs to be part of the model after causes for the DHWE are explored. Real data sets are used to illustrate the application of the methodology and its implication in genetic association studies. Our analysis and interpretation touch on issues such as genotyping errors, population selection, population stratification, or the study sampling plan, that all could be the cause of DHWE.
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Affiliation(s)
- Chang Yu
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2158, USA.
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Recovering unused information in genome-wide association studies: the benefit of analyzing SNPs out of Hardy-Weinberg equilibrium. Eur J Hum Genet 2009; 17:1676-82. [PMID: 19491930 DOI: 10.1038/ejhg.2009.85] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Although the rapid advancements in high throughput genotyping technology have made genome-wide association studies possible, these studies remain an expensive undertaking, especially when considering the large sample sizes necessary to find the small to moderate effect sizes that define complex diseases. It is therefore prudent to utilize all possible information contained in a genome-wide scan. We propose a straightforward analytical approach that tests often unused SNP data without sacrificing statistical validity. We simulate genotype miscalls under a variety of models consistent with observed miscall rates and test for departures from HWE using the standard Pearson's chi(2)-test. We find that true disease susceptibility loci subjected to various patterns of genotype miscalls can be largely out of HWE and, thus, be candidates for removal before association testing. These loci, we demonstrate, can maintain sufficient statistical power even under extreme error models. We additionally show that random miscalls of null SNPs, independent of the phenotype, do not induce bias in case-control or cohort studies, and we suggest that a significant HWE test should not prevent a SNP from being tested when conducting genome-wide association studies in these scenarios. However, association findings for SNPs that are out of HWE must be treated more carefully than 'regular' findings, for example, by re-genotyping the SNP in the same study using a different genotyping technology.
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Ray LA, Hutchison KE. Associations among GABRG1, level of response to alcohol, and drinking behaviors. Alcohol Clin Exp Res 2009; 33:1382-90. [PMID: 19426171 DOI: 10.1111/j.1530-0277.2009.00968.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND Recent studies of the genetics of alcoholism have focused on a cluster of genes encoding for gamma-aminobutyric acid (GABA(A)) receptor subunits, which is thought to play a role in the expression of addiction phenotypes. This study examined allelic associations between 2 single nucleotide polymorphisms (SNPs) of the GABRG1 gene (rs1391166 and rs1497571) and alcohol phenotypes, namely level of response to alcohol, alcohol use patterns, and alcohol-related problems. METHOD Participants were non-treatment-seeking seeking hazardous drinkers (n = 124) who provided DNA samples, participated in a face-to-face interview for level of response to alcohol, and completed a series of drinking and individual differences measures. RESULTS Analyses revealed that a SNP of the GABRG1 gene (rs1497571) was associated with level of response to alcohol and drinking patterns in this subclinical sample. Follow-up mediational analyses were also conducted to examine putative mechanisms underlying these associations. DISCUSSION These findings replicate and extend recent research suggesting that genetic variation at the GABRG1 locus may underlie the expression of alcohol phenotypes, including level of response to alcohol.
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Affiliation(s)
- Lara A Ray
- Department of Psychology, University of California , Los Angeles, California 90095-1563, USA.
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Little J, Higgins JPT, Ioannidis JPA, Moher D, Gagnon F, von Elm E, Khoury MJ, Cohen B, Davey-Smith G, Grimshaw J, Scheet P, Gwinn M, Williamson RE, Zou GY, Hutchings K, Johnson CY, Tait V, Wiens M, Golding J, van Duijn C, McLaughlin J, Paterson A, Wells G, Fortier I, Freedman M, Zecevic M, King R, Infante-Rivard C, Stewart A, Birkett N. STrengthening the REporting of Genetic Association studies (STREGA)--an extension of the STROBE statement. Eur J Clin Invest 2009; 39:247-66. [PMID: 19297801 PMCID: PMC2730482 DOI: 10.1111/j.1365-2362.2009.02125.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Making sense of rapidly evolving evidence on genetic associations is crucial to making genuine advances in human genomics and the eventual integration of this information in the practice of medicine and public health. Assessment of the strengths and weaknesses of this evidence, and hence the ability to synthesize it, has been limited by inadequate reporting of results. The STrengthening the REporting of Genetic Association studies (STREGA) initiative builds on the STrengthening the Reporting of OBservational Studies in Epidemiology (STROBE) Statement and provides additions to 12 of the 22 items on the STROBE checklist. The additions concern population stratification, genotyping errors, modelling haplotype variation, Hardy-Weinberg equilibrium, replication, selection of participants, rationale for choice of genes and variants, treatment effects in studying quantitative traits, statistical methods, relatedness, reporting of descriptive and outcome data and the volume of data issues that are important to consider in genetic association studies. The STREGA recommendations do not prescribe or dictate how a genetic association study should be designed, but seek to enhance the transparency of its reporting, regardless of choices made during design, conduct or analysis.
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Affiliation(s)
- Julian Little
- Canada Research Chair in Human Genome Epidemiology, Ottawa, ON, Canada.
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Little J, Higgins JPT, Ioannidis JPA, Moher D, Gagnon F, von Elm E, Khoury MJ, Cohen B, Davey-Smith G, Grimshaw J, Scheet P, Gwinn M, Williamson RE, Zou GY, Hutchings K, Johnson CY, Tait V, Wiens M, Golding J, van Duijn C, McLaughlin J, Paterson A, Wells G, Fortier I, Freedman M, Zecevic M, King R, Infante-Rivard C, Stewart A, Birkett N. STrengthening the REporting of Genetic Association Studies (STREGA): an extension of the STROBE statement. PLoS Med 2009; 6:e22. [PMID: 19192942 PMCID: PMC2634792 DOI: 10.1371/journal.pmed.1000022] [Citation(s) in RCA: 322] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Making sense of rapidly evolving evidence on genetic associations is crucial to making genuine advances in human genomics and the eventual integration of this information in the practice of medicine and public health. Assessment of the strengths and weaknesses of this evidence, and hence the ability to synthesize it, has been limited by inadequate reporting of results. The STrengthening the REporting of Genetic Association studies (STREGA) initiative builds on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement and provides additions to 12 of the 22 items on the STROBE checklist. The additions concern population stratification, genotyping errors, modelling haplotype variation, Hardy-Weinberg equilibrium, replication, selection of participants, rationale for choice of genes and variants, treatment effects in studying quantitative traits, statistical methods, relatedness, reporting of descriptive and outcome data, and the volume of data issues that are important to consider in genetic association studies. The STREGA recommendations do not prescribe or dictate how a genetic association study should be designed but seek to enhance the transparency of its reporting, regardless of choices made during design, conduct, or analysis.
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Affiliation(s)
- Julian Little
- Canada Research Chair in Human Genome Epidemiology, University of Ottawa, Ottawa, Ontario, Canada.
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Little J, Higgins JPT, Ioannidis JPA, Moher D, Gagnon F, von Elm E, Khoury MJ, Cohen B, Davey-Smith G, Grimshaw J, Scheet P, Gwinn M, Williamson RE, Zou GY, Hutchings K, Johnson CY, Tait V, Wiens M, Golding J, van Duijn C, McLaughlin J, Paterson A, Wells G, Fortier I, Freedman M, Zecevic M, King R, Infante-Rivard C, Stewart A, Birkett N. Strengthening the reporting of genetic association studies (STREGA): an extension of the STROBE statement. Eur J Epidemiol 2009; 24:37-55. [PMID: 19189221 PMCID: PMC2764094 DOI: 10.1007/s10654-008-9302-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2008] [Accepted: 11/04/2008] [Indexed: 02/02/2023]
Abstract
Making sense of rapidly evolving evidence on genetic associations is crucial to making genuine advances in human genomics and the eventual integration of this information in the practice of medicine and public health. Assessment of the strengths and weaknesses of this evidence, and hence the ability to synthesize it, has been limited by inadequate reporting of results. The STrengthening the REporting of Genetic Association studies (STREGA) initiative builds on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement and provides additions to 12 of the 22 items on the STROBE checklist. The additions concern population stratification, genotyping errors, modeling haplotype variation, Hardy–Weinberg equilibrium, replication, selection of participants, rationale for choice of genes and variants, treatment effects in studying quantitative traits, statistical methods, relatedness, reporting of descriptive and outcome data, and the volume of data issues that are important to consider in genetic association studies. The STREGA recommendations do not prescribe or dictate how a genetic association study should be designed but seek to enhance the transparency of its reporting, regardless of choices made during design, conduct, or analysis.
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Affiliation(s)
- Julian Little
- Canada Research Chair in Human Genome Epidemiology, Toronto, ON, Canada.
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Little J, Higgins JPT, Ioannidis JPA, Moher D, Gagnon F, von Elm E, Khoury MJ, Cohen B, Davey-Smith G, Grimshaw J, Scheet P, Gwinn M, Williamson RE, Zou GY, Hutchings K, Johnson CY, Tait V, Wiens M, Golding J, van Duijn C, McLaughlin J, Paterson A, Wells G, Fortier I, Freedman M, Zecevic M, King R, Infante-Rivard C, Stewart A, Birkett N. Strengthening the reporting of genetic association studies (STREGA): an extension of the STROBE Statement. Hum Genet 2009; 125:131-51. [DOI: 10.1007/s00439-008-0592-7] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 11/09/2008] [Indexed: 12/21/2022]
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Won S, Elston RC. The power of independent types of genetic information to detect association in a case-control study design. Genet Epidemiol 2008; 32:731-56. [DOI: 10.1002/gepi.20341] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Zintzaras E. Variance estimation of allele-based odds ratio in the absence of Hardy-Weinberg equilibrium. Eur J Epidemiol 2008; 23:323-6. [PMID: 18404407 DOI: 10.1007/s10654-008-9242-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 03/23/2008] [Indexed: 11/24/2022]
Abstract
In gene-disease association studies, deviation from Hardy-Weinberg equilibrium in controls may cause bias in estimating the allele-based estimates of genetic effects. An approach to adjust the variance of allele-based odds ratio for Hardy-Weinberg equilibrium deviation is proposed. Such adjustments have been introduced for estimating relative risks of genotype contrasts and differences in allele frequency; however, an adjustment of odds ratios for allele frequencies still does not exist. The approach was based on the delta method in combination with the Woolf's logit interval method and the disequilibrium coefficient. The proposed variance adjustment provided better power than the unadjusted one to detect significant estimates of odds ratio and it improved the variance estimation.
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Affiliation(s)
- Elias Zintzaras
- Department of Biomathematics, University of Thessaly School of Medicine, Papakyriazi 22, Larissa 41222, Greece.
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Rohlfs RV, Weir BS. Distributions of Hardy-Weinberg equilibrium test statistics. Genetics 2008; 180:1609-16. [PMID: 18791257 PMCID: PMC2581961 DOI: 10.1534/genetics.108.088005] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Accepted: 09/10/2008] [Indexed: 01/27/2023] Open
Abstract
It is well established that test statistics and P-values derived from discrete data, such as genetic markers, are also discrete. In most genetic applications, the null distribution for a discrete test statistic is approximated with a continuous distribution, but this approximation may not be reasonable. In some cases using the continuous approximation for the expected null distribution may cause truly null test statistics to appear nonnull. We explore the implications of using continuous distributions to approximate the discrete distributions of Hardy-Weinberg equilibrium test statistics and P-values. We derive exact P-value distributions under the null and alternative hypotheses, enabling a more accurate analysis than is possible with continuous approximations. We apply these methods to biological data and find that using continuous distribution theory with exact tests may underestimate the extent of Hardy-Weinberg disequilibrium in a sample. The implications may be most important for the widespread use of whole-genome case-control association studies and Hardy-Weinberg equilibrium (HWE) testing for data quality control.
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Affiliation(s)
- R V Rohlfs
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195-5065, USA.
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Conti DV, Lee W, Li D, Liu J, Van Den Berg D, Thomas PD, Bergen AW, Swan GE, Tyndale RF, Benowitz NL, Lerman C. Nicotinic acetylcholine receptor beta2 subunit gene implicated in a systems-based candidate gene study of smoking cessation. Hum Mol Genet 2008; 17:2834-48. [PMID: 18593715 PMCID: PMC2525499 DOI: 10.1093/hmg/ddn181] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 06/17/2008] [Indexed: 11/12/2022] Open
Abstract
Although the efficacy of pharmacotherapy for tobacco dependence has been previously demonstrated, there is substantial variability among individuals in treatment response. We performed a systems-based candidate gene study of 1295 single nucleotide polymorphisms (SNPs) in 58 genes within the neuronal nicotinic receptor and dopamine systems to investigate their role in smoking cessation in a bupropion placebo-controlled randomized clinical trial. Putative functional variants were supplemented with tagSNPs within each gene. We used global tests of main effects and treatment interactions, adjusting the P-values for multiple correlated tests. An SNP (rs2072661) in the 3' UTR region of the beta2 nicotinic acetylcholine receptor subunit (CHRNB2) has an impact on abstinence rates at the end of treatment (adjusted P = 0.01) and after a 6-month follow-up period (adjusted P = 0.0002). This latter P-value is also significant with adjustment for the number of genes tested. Independent of treatment at 6-month follow-up, individuals carrying the minor allele have substantially decreased the odds of quitting (OR = 0.31; 95% CI 0.18-0.55). Effect of estimates indicate that the treatment is more effective for individuals with the wild-type (OR = 2.14, 95% CI 1.20-3.81) compared with individuals carrying the minor allele (OR = 0.83, 95% CI 0.32-2.19), although this difference is only suggestive (P = 0.10). Furthermore, this SNP demonstrated a role in the time to relapse (P = 0.0002) and an impact on withdrawal symptoms at target quit date (TQD) (P = 0.0009). Overall, while our results indicate strong evidence for CHRNB2 in ability to quit smoking, these results require replication in an independent sample.
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Affiliation(s)
- David V Conti
- Department of Preventive Medicine, Keck School of Medicine, Zilkha Neurogenetics Institute, University of Southern California, 1501 San Pablo Street, ZNI 445, Los Angeles, CA 90089, USA.
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Deviations from Hardy-Weinberg proportions for multiple alleles under viability selection. Genet Res (Camb) 2008; 90:209-16. [PMID: 18426624 DOI: 10.1017/s0016672307009068] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Departures of genotype frequencies from Hardy-Weinberg proportions (HWP) for a single autosomal locus due to viability selection in a random mating population have been studied only for the two-allele case. In this article, the analysis of deviations from HWP due to constant viability selection is extended to multiple alleles. The deviations for an autosomal locus with k alleles are measured by means of k fii fixation indices for homozygotes and k(k-1)/2 fij fixation indices for heterozygotes, and expressions are obtained for these indices (FIS statistics) under the multiallele viability model. Furthermore, expressions for fii and fij when the multiallele polymorphism is at stable equilibrium are also derived and it is demonstrated that the pattern of multiallele Hardy-Weinberg deviations at equilibrium is characterized by a global heterozygote excess and a deficiency of each of the homozygotes. This pattern may be useful for detecting whether a given multiallelic polymorphism is at stable equilibrium in the population due to viability selection. An analysis of Hardy-Weinberg deviations from published data for the three-allele polymorphism at the beta-globin locus in human populations from West Africa is presented for illustration.
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Abstract
It has been stated that, when Hardy-Weinberg equilibrium (HWE) holds in the combined case-control samples, the allelic test is asymptotically equivalent to the trend test (for the additive model) for testing genetic association, and hence the allelic test should not be used. A recent publication shows that the allelic test and the trend test are asymptotically equivalent when HWE holds in the population. It is known that, when HWE does not hold, the trend test can still be used while the allelic test is no longer valid. Therefore, the allelic test is either not valid or is asymptotically equivalent to the trend test. It appears that the allelic test is a nuisance test. Can it be retired from the analysis of case-control association studies? It all depends on data and model assumptions. We give conditions under which the allelic test and the trend test are asymptotically equivalent under both null and alternative hypotheses.
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Affiliation(s)
- Gang Zheng
- Office of Biostatistics Research, DPPS, National Heart, Lung and Blood Institute, Bethesda, MD 20892-7913, USA.
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Zhang Q, Wang S, Ott J. Combining identity by descent and association in genetic case-control studies. BMC Genet 2008; 9:42. [PMID: 18601744 PMCID: PMC2483716 DOI: 10.1186/1471-2156-9-42] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2007] [Accepted: 07/05/2008] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND In human case-control association studies, one of the chi-square tests typically carried out is based on a 2 x 3 table of genotypes (homogeneity of three genotype frequencies in case and control individuals). We formulate the two degrees of freedom associated with a given genotype distribution in terms of two biologically relevant parameters, (1) the probability F that an individual's two alleles are identical by descent (IBD) and (2) the frequency p of one of the alleles. RESULTS Imposing the restriction, F > or = 0, makes some of the genotype frequencies invalid thereby reducing noise. We propose a new statistical association test, the FP test, by focusing on allele frequency differences between case and control individuals while allowing for suitable IBD probabilities. Power calculations show that (1) the practice of generally carrying out two association tests (allele and genotype test) has an increased type I error and (2) our test is more powerful than conventional genotype and allele tests under recessive trait inheritance, and at least as powerful as these conventional tests under dominant inheritance. CONCLUSION For dominant and recessive modes of inheritance, any apparent power gain by an allele test when carried out in conjunction with a genotype test tends to be purchased entirely by an increased rate of false positive results due to omission of a multiple testing correction. As an alternative to these two standard association tests, our FP test represents a convenient and more powerful alternative.
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Affiliation(s)
- Qingrun Zhang
- Beijing Institute of Genomics, Chinese Academy of Sciences, No. 7 Bei Tu Cheng West Road, Beijing 100029, PR China.
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