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Kelly LE, Chaudhry SA, Rieder MJ, ‘t Jong G, Moretti ME, Lausman A, Ross C, Berger H, Carleton B, Hayden MR, Madadi P, Koren G. A clinical tool for reducing central nervous system depression among neonates exposed to codeine through breast milk. PLoS One 2013; 8:e70073. [PMID: 23922910 PMCID: PMC3726489 DOI: 10.1371/journal.pone.0070073] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 06/14/2013] [Indexed: 11/19/2022] Open
Abstract
Background Neonates are commonly exposed to maternal codeine through breast milk. Central Nervous System (CNS) depression has been reported in up to 24% of nurslings following codeine exposure. In 2009, we developed guidelines to improve the safety of codeine use during breastfeeding based on previously established pharmacogenetic and clinical risk factors. The primary objective of this study was to prospectively evaluate the effectiveness of these guidelines in ensuring neonatal safety. Methods and Findings Women taking codeine for pain following caesarean section were given safety guidelines, including advice to use the lowest codeine dose for no longer than four days and to switch to a non-opioid when possible. Mothers provided a saliva sample for analysis of genes involved in opioid disposition, metabolism and response. A total of 238 consenting women participated. Neonatal sedation was reported in 2.1% (5/238) of breastfeeding women taking codeine according to our safety guidelines. This rate was eight fold lower than that reported in previous prospective studies. Women reporting sedated infants were taking codeine for a significantly longer period of time (4.80±2.59 days vs. 2.52±1.58 days, p = 0.0018). While following the codeine safety guidelines, mothers were less likely to supplement with formula, reported lower rates of sedation in themselves and breastfed more frequently throughout the day when compared to previously reported rates. Genotyping analysis of cytochrome p450 2D6 (CYP2D6), uridine-diphosphate glucuronosyltransferase (UGT) 2B7, p-glycoprotein (ABCB1), the mu-opioid receptor (OPRM1) and catechol-o-demethyltransferase (COMT) did not predict codeine response in breastfeeding mother/infant pairs when following the safety guidelines. Conclusions The only cases of CNS depression occurred when the length of codeine use exceeded the guideline recommendations. Neonatal safety of codeine can be improved using evidence-based guidelines, even in those deemed by genetics to be at high risk for toxicity.
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Affiliation(s)
- Lauren E. Kelly
- Department of Physiology and Pharmacology, Schulich School of Medicine, University of Western Ontario, London, Ontario, Canada
- Department of Clinical Pharmacology, London Health Sciences Centre, London, Ontario, Canada
- Ivey Chair in Molecular Toxicology, University of Western Ontario, London, Ontario, Canada
| | - Shahnaz A. Chaudhry
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
- Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael J. Rieder
- Department of Physiology and Pharmacology, Schulich School of Medicine, University of Western Ontario, London, Ontario, Canada
- Department of Clinical Pharmacology, London Health Sciences Centre, London, Ontario, Canada
| | - Geert ‘t Jong
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
- Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Myla E. Moretti
- Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Andrea Lausman
- Department of obstetrics and gynecology, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Colin Ross
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Howard Berger
- Department of obstetrics and gynecology, St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Bruce Carleton
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
- Child and Family Research Institute, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Parvaz Madadi
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
- Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Gideon Koren
- Ivey Chair in Molecular Toxicology, University of Western Ontario, London, Ontario, Canada
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
- Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, Toronto, Ontario, Canada
- * E-mail:
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Semaka A, Kay C, Doty C, Collins JA, Bijlsma EK, Richards F, Goldberg YP, Hayden MR. CAG size-specific risk estimates for intermediate allele repeat instability in Huntington disease. J Med Genet 2013; 50:696-703. [PMID: 23896435 DOI: 10.1136/jmedgenet-2013-101796] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION New mutations for Huntington disease (HD) occur due to CAG repeat instability of intermediate alleles (IA). IAs have between 27 and 35 CAG repeats, a range just below the disease threshold of 36 repeats. While they usually do not confer the HD phenotype, IAs are prone to paternal germline CAG repeat instability. Consequently, they may expand into the HD range upon transmission to the next generation, producing a new mutation. Quantified risk estimates for IA repeat instability are extremely limited but needed to inform clinical practice. METHODS Using small-pool PCR of sperm DNA from Caucasian men, we examined the frequency and magnitude of CAG repeat instability across the entire range of intermediate CAG sizes. The CAG size-specific risk estimates generated are based on the largest sample size ever examined, including 30 IAs and 18 198 sperm. RESULTS Our findings demonstrate a significant risk of new mutations. While all intermediate CAG sizes demonstrated repeat expansion into the HD range, alleles with 34 and 35 CAG repeats were associated with the highest risk of a new mutation (2.4% and 21.0%, respectively). IAs with ≥33 CAG repeats showed a dramatic increase in the frequency of instability and a switch towards a preponderance of repeat expansions over contractions. CONCLUSIONS These data provide novel insights into the origins of new mutations for HD. The CAG size-specific risk estimates inform clinical practice and provide accurate risk information for persons who receive an IA predictive test result.
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Affiliation(s)
- Alicia Semaka
- Department of Medical Genetics, Centre for Molecular Medicine & Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
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153
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Bhavsar AP, Brown NF, Stoepel J, Wiermer M, Martin DDO, Hsu KJ, Imami K, Ross CJ, Hayden MR, Foster LJ, Li X, Hieter P, Finlay BB. The Salmonella type III effector SspH2 specifically exploits the NLR co-chaperone activity of SGT1 to subvert immunity. PLoS Pathog 2013; 9:e1003518. [PMID: 23935490 PMCID: PMC3723637 DOI: 10.1371/journal.ppat.1003518] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 06/08/2013] [Indexed: 11/19/2022] Open
Abstract
To further its pathogenesis, S. Typhimurium delivers effector proteins into host cells, including the novel E3 ubiquitin ligase (NEL) effector SspH2. Using model systems in a cross-kingdom approach we gained further insight into the molecular function of this effector. Here, we show that SspH2 modulates innate immunity in both mammalian and plant cells. In mammalian cell culture, SspH2 significantly enhanced Nod1-mediated IL-8 secretion when transiently expressed or bacterially delivered. In addition, SspH2 also enhanced an Rx-dependent hypersensitive response in planta. In both of these nucleotide-binding leucine rich repeat receptor (NLR) model systems, SspH2-mediated phenotypes required its catalytic E3 ubiquitin ligase activity and interaction with the conserved host protein SGT1. SGT1 has an essential cell cycle function and an additional function as an NLR co-chaperone in animal and plant cells. Interaction between SspH2 and SGT1 was restricted to SGT1 proteins that have NLR co-chaperone function and accordingly, SspH2 did not affect SGT1 cell cycle functions. Mechanistic studies revealed that SspH2 interacted with, and ubiquitinated Nod1 and could induce Nod1 activity in an agonist-independent manner if catalytically active. Interestingly, SspH2 in vitro ubiquitination activity and protein stability were enhanced by SGT1. Overall, this work adds to our understanding of the sophisticated mechanisms used by bacterial effectors to co-opt host pathways by demonstrating that SspH2 can subvert immune responses by selectively exploiting the functions of a conserved host co-chaperone.
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Affiliation(s)
- Amit P. Bhavsar
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Nat F. Brown
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for High-Throughput Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jan Stoepel
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Marcel Wiermer
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Dale D. O. Martin
- Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Karolynn J. Hsu
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Koshi Imami
- Centre for High-Throughput Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin J. Ross
- Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pediatrics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Leonard J. Foster
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for High-Throughput Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Xin Li
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Botany, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Phil Hieter
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - B. Brett Finlay
- Michael Smith Laboratories, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, British Columbia, Canada
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154
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Bochem AE, van Capelleveen JC, Dallinga-Thie GM, Schimmel AWM, Motazacker MM, Tietjen I, Singaraja RR, Hayden MR, Kastelein JJP, Stroes ESG, Hovingh GK. Two novel mutations in apolipoprotein C3 underlie atheroprotective lipid profiles in families. Clin Genet 2013; 85:433-40. [PMID: 23701270 DOI: 10.1111/cge.12201] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 10/26/2022]
Abstract
Apolipoprotein C3 (APOC3) mutations carriers typically display high plasma high-density lipoprotein cholesterol (HDL-C) and low triglycerides (TGs). We set out to investigate the prevalence and clinical consequences of APOC3 mutations in individuals with hyperalphalipoproteinemia. Two novel mutations (c.-13-2A>G and c.55+1G>A) and one known mutation (c.127G>A;p.Ala43Thr) were found. Lipid profiles and apoCIII isoform distributions were measured. c.55+1G>A mutation carriers displayed higher HDL-C percentiles (35.6 ± 35.8 vs 99.0 ± 0, p = 0.002) and lower TGs (0.51 (0.37-0.61) vs 1.42 (1.12-1.81) mmol/l, p = 0.007) and apoCIII levels (4.24 ± 1.57 vs 7.33 ± 3.61 mg/dl, p = 0.18). c.-13-2A>G mutation carriers did not display significantly different HDL-C levels (84.0 ± 30.0 vs 63.7 ± 45.7, p = 0.50), a trend towards lower TGs [0.71 (0.54 to 0.78) vs 0.85 (0.85 to -) mmol/l, p = 0.06] and significantly lower apoCIII levels (3.09 ± 1.08 vs 11.45 ± 1.06 mg/dl, p = 0.003). p.Ala43Thr mutation carriers displayed a trend towards higher HDL-C percentiles (91.2 ± 31.8 vs 41.0 ± 29.7 mmol/l, p = 0.06) and significantly lower TGs [0.58 (0.36-0.63) vs 0.95 (0.71-1.20) mmol/l, p = 0.02] and apoCIII levels (4.92 ± 2.33 vs 6.60 ± 1.60, p = 0.25). Heterozygosity for APOC3 mutations results in high HDL-C and low TGs and apoCIII levels. This favourable lipid profile in patients with genetically low apoCIII levels holds promise for current studies investigating the potential of apoCIII inhibition as a novel therapeutic in cardiovascular disease prevention.
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155
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Karasinska JM, de Haan W, Franciosi S, Ruddle P, Fan J, Kruit JK, Stukas S, Lütjohann D, Gutmann DH, Wellington CL, Hayden MR. ABCA1 influences neuroinflammation and neuronal death. Neurobiol Dis 2013; 54:445-55. [DOI: 10.1016/j.nbd.2013.01.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 01/04/2013] [Accepted: 01/17/2013] [Indexed: 11/29/2022] Open
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156
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Shaw K, Amstutz U, Castro-Pastrana L, Loo TT, Ross CJ, Ito S, Reider MJ, Maher M, Macleod S, Koren G, Hayden MR, Carleton BC. Pharmacogenomic investigation of adverse drug reactions(ADRs): the ADR prioritization tool, APT. J Popul Ther Clin Pharmacol 2013; 20:e110-e127. [PMID: 23824325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND The impact of genetic factors on the risk of adverse drug reactions (ADRs) is being increasingly recognized as clinically important. ADR Prioritization Tool (APT) was developed to facilitate the prioritization of drugs and their associated ADRs for future pharmacogenomic studies. OBJECTIVES To describe a novel tool developed for the prioritization of pharmacogenomic investigation of ADRs and discuss the impact of specific scoring criteria. METHODS APT scores were based on 25 key scientific and feasibility criteria relevant for clinical research evaluating the genetic basis of ADRs, with a maximum possible score of 60 points. The tool was independently applied to five ADRs (warfarin-induced bleeding/thrombosis, cisplatin-induced ototoxicity, methotrexate-induced neutropenia, carbamazepine-induced Stevens-Johnson syndrome, and abacavir-induced hypersensitivity) by two researchers. Scores were compared using the intraclass correlation coefficient (ICC) to determine level of agreement. RESULTS Overall scores for target ADRs ranged from 19.5 to 44 points (33-73% of maximum possible score). Cisplatin-induced ototoxicity, a frequent and severe ADR, received the highest score (44). Lower scores were obtained for abacavir-induced hypersensitivity (19.5) and methotrexate-induced neutropenia (28). High agreement was observed between the scientific, feasibility, and total scores from two reviewers (ICC values = 0.895, 0.980, and 0.983, respectively). CONCLUSION Application of APT enables simple and direct comparison of potential study targets for research groups embarking on pharmacogenomic investigation of ADRs. Research teams will be able to identify which study targets are best suited for their research environment and discern how to optimize resource allocation for successful discovery and replication of clinically relevant biomarkers.
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Affiliation(s)
- Kaitlyn Shaw
- Faculty of Medicine, University of British Columbia, Canada
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157
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Ross CJD, Katzov-Eckert H, Dubé MP, Brooks B, Rassekh SR, Barhdadi A, Feroz-Zada Y, Visscher H, Brown AMK, Rieder MJ, Rogers PC, Phillips MS, Carleton BC, Hayden MR. Erratum: Genetic variants in TPMT and COMT are associated with hearing loss in children receiving cisplatin chemotherapy. Nat Genet 2013. [DOI: 10.1038/ng.0513-578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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158
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Lam J, Woodall K, Solbeck P, Ross CJD, Carleton B, Hayden MR, Koren G, Madadi P. An investigation of morphine‐to‐codeine metabolic ratios in postmortem blood, drug interactions, and cytochrome P450 2D6 (CYP2D6) genotype. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.666.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jessica Lam
- Division of Clinical Pharmacology and ToxicologyHospital for Sick ChildrenTorontoONCanada
| | - Karen Woodall
- Department of ToxicologyCenter for Forensic ScienceTorontoONCanada
| | - Patricia Solbeck
- Department of ToxicologyCenter for Forensic ScienceTorontoONCanada
| | - Colin JD Ross
- Department of Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
| | - Bruce Carleton
- Child and Family Research InstituteChildren's and Women's Health Centre of British ColumbiaVancouverBCCanada
| | - Michael R Hayden
- Department of Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
| | - Gideon Koren
- Division of Clinical Pharmacology and ToxicologyHospital for Sick ChildrenTorontoONCanada
| | - Parvaz Madadi
- Division of Clinical Pharmacology and ToxicologyHospital for Sick ChildrenTorontoONCanada
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159
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Abstract
Over the last few decades, cure rates for pediatric cancer have increased dramatically, and now over 80 % of children with cancer are cured of their disease. This improvement in cure has come with a significant cost, with many children suffering irreversible, life-threatening, or long-lasting toxicities due to the medications required during their treatment. In the last 2 decades, major technological advances in genomics and the mapping of the human genome have made it possible to identify genetic differences between children in order to investigate differing responses to cancer therapy and to help explain why children treated with the same medications can have different outcomes. The emerging field of pharmacogenomics has had many important findings in pediatric cancer. The focus of this review is drug toxicity in pediatric cancer and the use of pharmacogenomics to reduce these adverse drug reactions, with a specific focus on thiopurines, methotrexate, cisplatin, vincristine and anthracyclines. Future areas of research and the need for international collaboration are discussed.
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Affiliation(s)
- Shahrad Rod Rassekh
- Department of Pediatrics, Division of Pediatric Hematology/Oncology/BMT, University of British Columbia, Vancouver, BC, Canada.
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160
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Aminkeng F, Ross CJD, Rassekh RS, Brunham LR, Weissman C, Dube M, Visscher H, Rieder MJ, Carleton BC, Hayden MR. Predicting Anthracycline‐induced Cardiotoxicity in Children – Genome‐Wide Association Study. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.663.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Colin JD Ross
- PediatricsUniversity of British ColumbiaVancouverBCCanada
| | - Rod S Rassekh
- PediatricsBc Children and Women HospitalVancouverBCCanada
| | - Liam R Brunham
- Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
| | - Cory Weissman
- Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
| | | | - Henk Visscher
- Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
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161
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Amstutz U, Loo TT, Gylling HM, Rassekh R, Hukin J, Zada YF, Dubé M, Brown AM, Phillips MS, Hayden MR, Ross CJ, Carleton BC. Pharmacogenomics of vincristine‐induced neurotoxicity in pediatric cancer patients. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.666.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ursula Amstutz
- PediatricsUniversity of British ColumbiaVancouverBCCanada
| | | | | | - Rod Rassekh
- PediatricsUniversity of British ColumbiaVancouverBCCanada
- BC Children's HospitalVancouverBCCanada
| | - Juliette Hukin
- PediatricsUniversity of British ColumbiaVancouverBCCanada
- BC Children's HospitalVancouverBCCanada
| | | | | | - Andrew M Brown
- Montreal Heart InstituteUniversité de MontrealMontrealQCCanada
| | | | | | - Colin J Ross
- PediatricsUniversity of British ColumbiaVancouverBCCanada
- Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
| | - Bruce C Carleton
- PediatricsUniversity of British ColumbiaVancouverBCCanada
- BC Children's HospitalVancouverBCCanada
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162
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Shaw K, Amstutz U, Hildebrand C, Rassekh SR, Dubé M, Hayden MR, Ross CJ, Carleton BC. Pharmacogenetics of warfarin safety and effectiveness in children. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.673.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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163
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Abstract
The concept that a specific alteration in an individual’s DNA can result in disease is central to our notion of molecular medicine. The molecular basis of more than 3,500 Mendelian disorders has now been identified. In contrast, the identification of genes for common disease has been much more challenging. We discuss historical and contemporary approaches to disease gene identification, focusing on novel opportunities such as the use of population extremes and the identification of rare variants. While our ability to sequence DNA has advanced dramatically, assigning function to a given sequence change remains a major challenge, highlighting the need for both bioinformatics and functional approaches to appropriately interpret these data. We review progress in mapping and identifying human disease genes and discuss future challenges and opportunities for the field.
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Affiliation(s)
- Liam R. Brunham
- Department of Medicine, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, Canada
- Translational Laboratory for Genetic Medicine, National University of Singapore and the Association for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Michael R. Hayden
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, Canada
- Translational Laboratory for Genetic Medicine, National University of Singapore and the Association for Science, Technology and Research (A*STAR), Singapore, Singapore
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164
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Baine FK, Kay C, Ketelaar ME, Collins JA, Semaka A, Doty CN, Krause A, Greenberg LJ, Hayden MR. Huntington disease in the South African population occurs on diverse and ethnically distinct genetic haplotypes. Eur J Hum Genet 2013; 21:1120-7. [PMID: 23463025 DOI: 10.1038/ejhg.2013.2] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/12/2012] [Accepted: 12/28/2012] [Indexed: 11/09/2022] Open
Abstract
Huntington disease (HD) is a neurodegenerative disorder resulting from the expansion of a CAG trinucleotide repeat in the huntingtin (HTT) gene. Worldwide prevalence varies geographically with the highest figures reported in populations of European ancestry. HD in South Africa has been reported in Caucasian, black and mixed subpopulations, with similar estimated prevalence in the Caucasian and mixed groups and a lower estimate in the black subpopulation. Recent studies have associated specific HTT haplotypes with HD in distinct populations. Expanded HD alleles in Europe occur predominantly on haplogroup A (specifically high-risk variants A1/A2), whereas in East Asian populations, HD alleles are associated with haplogroup C. Whether specific HTT haplotypes associate with HD in black Africans and how these compare with haplotypes found in European and East Asian populations remains unknown. The current study genotyped the HTT region in unaffected individuals and HD patients from each of the South African subpopulations, and haplotypes were constructed. CAG repeat sizes were determined and phased to haplotype. Results indicate that HD alleles from Caucasian and mixed patients are predominantly associated with haplogroup A, signifying a similar European origin for HD. However, in black patients, HD occurs predominantly on haplogroup B, suggesting several distinct origins of the mutation in South Africa. The absence of high-risk variants (A1/A2) in the black subpopulation may also explain the reported low prevalence of HD. Identification of haplotypes associated with HD-expanded alleles is particularly relevant to the development of population-specific therapeutic targets for selective suppression of the expanded HTT transcript.
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Affiliation(s)
- Fiona K Baine
- 1] Division of Human Genetics, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa [2] Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
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165
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Sutton LM, Sanders SS, Butland SL, Singaraja RR, Franciosi S, Southwell AL, Doty CN, Schmidt ME, Mui KKN, Kovalik V, Young FB, Zhang W, Hayden MR. Hip14l-deficient mice develop neuropathological and behavioural features of Huntington disease. Hum Mol Genet 2013; 22:452-65. [PMID: 23077216 DOI: 10.1093/hmg/dds441] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Palmitoylation, the dynamic post-translational addition of the lipid, palmitate, to proteins by Asp-His-His-Cys-containing palmitoyl acyltransferase (PAT) enzymes, modulates protein function and localization and plays a key role in the nervous system. Huntingtin-interacting protein 14 (HIP14), a well-characterized neuronal PAT, has been implicated in the pathogenesis of Huntington disease (HD), a fatal neurodegenerative disease associated with motor, psychiatric and cognitive symptoms, caused by a CAG expansion in the huntingtin gene (HTT). Mice deficient for Hip14 expression develop neuropathological and behavioural features similar to HD, and the catalytic activity of HIP14 is impaired in HD mice, most likely due to the reduced interaction of HIP14 with HTT. Huntingtin-interacting protein 14-like (HIP14L) is a paralog of HIP14, with identical domain structure. Together, HIP14 and HIP14L are the major PATs for HTT. Here, we report the characterization of a Hip14l-deficient mouse model, which develops adult-onset, widespread and progressive neuropathology accompanied by early motor deficits in climbing, impaired motor learning and reduced palmitoylation of a novel HIP14L substrate: SNAP25. Although the phenotype resembles that of the Hip14(-/-) mice, a more progressive phenotype, similar to that of the YAC128 transgenic mouse model of HD, is observed. In addition, HIP14L interacts less with mutant HTT than the wild-type protein, suggesting that reduced HIP14L-dependent palmitoylation of neuronal substrates may contribute to the pathogenesis of HD. Thus, both HIP14 and HIP14L may be dysfunctional in the disease.
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Affiliation(s)
- Liza M Sutton
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
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Hawkins AK, Creighton S, Hayden MR. When access is an issue: exploring barriers to predictive testing for Huntington disease in British Columbia, Canada. Eur J Hum Genet 2013; 21:148-53. [PMID: 22781094 PMCID: PMC3548262 DOI: 10.1038/ejhg.2012.147] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 04/20/2012] [Accepted: 05/21/2012] [Indexed: 12/31/2022] Open
Abstract
Predictive testing (PT) for Huntington disease (HD) requires several in-person appointments. This requirement may be a barrier to testing so that at risk individuals do not realize the potential benefits of PT. To understand the obstacles to PT in terms of the accessibility of services, as well as exploring mechanisms by which this issue may be addressed, we conducted an interview study of individuals at risk for HD throughout British Columbia, Canada. Results reveal that the accessibility of PT can be a barrier for two major reasons: distance and the inflexibility of the testing process. Distance is a structural barrier, and relates to the time and travel required to access PT, the financial and other opportunity costs associated with taking time away from work and family to attend appointments and the stress of navigating urban centers. The inflexibility of the testing process barrier relates to the emotional and psychological accessibility of PT. The results of the interview study reveal that there are access barriers to PT that deter individuals from receiving the support, information and counseling they require. What makes accessibility of PT services important is not just that it may result in differences in quality of life and care, but because these differences may be addressed with creative and adaptable solutions in the delivery of genetic services. The study findings underscore the need for us to rethink and personalize the way we deliver such services to improve access issues to prevent inequities in the health care system.
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Affiliation(s)
- Alice K Hawkins
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada.
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167
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Hayden MR. Special new feature in Clinical Genetics. Clin Genet 2013. [DOI: 10.1111/cge.12067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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168
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Singaraja RR, Sivapalaratnam S, Hovingh K, Dubé MP, Castro-Perez J, Collins HL, Adelman SJ, Riwanto M, Manz J, Hubbard B, Tietjen I, Wong K, Mitnaul LJ, van Heek M, Lin L, Roddy TA, McEwen J, Dallinge-Thie G, van Vark-van der Zee L, Verwoert G, Winther M, van Duijn C, Hofman A, Trip MD, Marais AD, Asztalos B, Landmesser U, Sijbrands E, Kastelein JJ, Hayden MR. The impact of partial and complete loss-of-function mutations in endothelial lipase on high-density lipoprotein levels and functionality in humans. ACTA ACUST UNITED AC 2012; 6:54-62. [PMID: 23243195 DOI: 10.1161/circgenetics.111.962613] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Endothelial lipase is a phospholipase with activity against high-density lipoprotein. Although a small number of mutations in LIPG have been described, the role of LIPG in protection against atherosclerosis is unclear. METHODS AND RESULTS We identified 8 loss-of-function (LOF) mutations in LIPG in individuals with high-density lipoprotein cholesterol. Functional analysis confirmed that most rare mutations abolish lipase activity in vitro, indicating complete LOF, whereas 2 more common mutations N396S and R476W reduce activity by ≈50%, indicating partial LOF and implying ≈50% and ≈75% remaining endothelial lipase function in heterozygous complete LOF and partial LOF mutation carriers, respectively. complete LOF mutation carriers had significantly higher plasma high-density lipoprotein cholesterol levels compared with partial LOF mutation carriers. Apolipoprotein B-depleted serum from complete LOF carriers showed significantly enhanced cholesterol efflux acceptor capacity, whereas only trends were observed in partial LOF carriers. Carriers of LIPG mutations exhibited trends toward reduced coronary artery disease in 4 independent cohorts (meta-analysis odds ratio, 0.7; P=0.04). CONCLUSIONS Our data suggest that the impact of LIPG mutations is directly related to their effect on endothelial lipase function and support that antagonism of endothelial lipase function improves cardioprotection.
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169
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Khetani JD, Madadi P, Sommer DD, Reddy D, Sistonen J, Ross CJD, Carleton BC, Hayden MR, Koren G. Apnea and oxygen desaturations in children treated with opioids after adenotonsillectomy for obstructive sleep apnea syndrome: a prospective pilot study. Paediatr Drugs 2012; 14:411-5. [PMID: 23013460 DOI: 10.2165/11633570-000000000-00000] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BACKGROUND Recent case reports have alerted the medical community of fatality in children receiving codeine after tonsillectomy and/or adenoidectomy for obstructive sleep apnea syndrome. OBJECTIVE The objective of this study was to compare the rates of oxygen desaturation before and after adenotonsillectomy in children with obstructive sleep apnea syndrome (OSAS), and to examine the relationship between cytochrome P450 2D6 (CYP2D6) genotype and respiratory events. STUDY DESIGN This was a prospective observational study. METHODS Twenty-six children with OSAS (mean age 78 months, range 1.8-17 years) who underwent adenotonsillectomy were studied. CYP2D6 genotype was characterized in 21 of these children. The primary endpoints of the study were the change in the rate of desaturation and in the nadir oxygen saturation values before and in the first 24 hours after surgery as measured by pulse oximetry. RESULTS Twenty-two children received codeine and four were managed with hydrocodone. There was no post-operative improvement in the mean rate of desaturation (1.84 ± 1.45/hour pre-operative vs 2.97 ± 3.3/hour post-operative; p = 0.119; 95% CI -2.56, 0.313), or the post-operative nadir of oxygen saturation (85.2 ± 5.8% pre-operative vs 84.0 ± 6.8% post-operative; p = 0.632; 95% CI -3.00, 4.84) on the night after surgery. Prior to surgery, six children had an oxygen saturation nadir <80%, while post-surgery, the number increased to eight children. Ten children improved their parameters after surgery. CYP2D6 genotype by itself did not predict the changes in desaturation or nadir. CONCLUSION Post-operative use of opioids following OSAS may not be safe for all children. It is conceivable that if the child is among the significant proportion that experiences increased oxygen desaturations, the CNS depressing effects of codeine or hydrocodone and their respectively potent morphine or hydromorphone metabolites can further compromise respiratory drive. Larger studies are needed to investigate the potential contribution of CYP2D6 genotype.
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Affiliation(s)
- Justin D Khetani
- Department of Surgery, OtolaryngologyHead Neck Surgery Division, McMaster University, Hamilton, ON, Canada
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170
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Pouladi MA, Brillaud E, Xie Y, Conforti P, Graham RK, Ehrnhoefer DE, Franciosi S, Zhang W, Poucheret P, Compte E, Maurel JC, Zuccato C, Cattaneo E, Néri C, Hayden MR. NP03, a novel low-dose lithium formulation, is neuroprotective in the YAC128 mouse model of Huntington disease. Neurobiol Dis 2012; 48:282-9. [DOI: 10.1016/j.nbd.2012.06.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 06/25/2012] [Accepted: 06/29/2012] [Indexed: 11/28/2022] Open
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171
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Hawkins AK, Creighton S, Ho A, McManus B, Hayden MR. Providing predictive testing for Huntington disease via telehealth: results of a pilot study in British Columbia, Canada. Clin Genet 2012; 84:60-4. [PMID: 23039041 DOI: 10.1111/cge.12033] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 10/02/2012] [Accepted: 10/02/2012] [Indexed: 01/18/2023]
Abstract
Predictive testing (PT) for Huntington disease (HD) usually requires several in-person appointments which acts as a barrier to testing for those from remote regions. This pilot study reports the use of telehealth PT to examine whether such telehealth testing improves access to HD PT while maintaining quality of care and support. Individuals underwent PT via the telehealth protocol or standard in-person protocol and were asked to complete surveys regarding their experience. Results reveal no significant differences between the in-person-tested and telehealth-tested groups with respect to quality of care, information, counselling and support. The majority of participants in both groups stated that pre-test counselling had provided them with sufficient knowledge about the advantages and disadvantages of undergoing testing, the opportunity to ask questions, and the ability to make an informed decision. The majority of participants in both groups were satisfied by the manner in which results were delivered and stated they had received sufficient information regarding the implications of these results. This study reveals that telehealth PT improves access while maintaining quality of care and support.
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Affiliation(s)
- A K Hawkins
- Department of Medical Genetics, Centre for Applied Ethics, University of British Columbia, 950 West 28th Ave, Vancouver, BC,
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172
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Southwell AL, Skotte NH, Bennett CF, Hayden MR. Antisense oligonucleotide therapeutics for inherited neurodegenerative diseases. Trends Mol Med 2012; 18:634-43. [PMID: 23026741 DOI: 10.1016/j.molmed.2012.09.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 08/25/2012] [Accepted: 09/07/2012] [Indexed: 12/12/2022]
Abstract
The rising median age of our population and the age-dependent risk of neurodegeneration translate to exponentially increasing numbers of afflicted individuals in the coming years. Although symptomatic treatments are available for some neurodegenerative diseases, most are only moderately efficacious and are often associated with significant side effects. The development of small molecule, disease-modifying drugs has been hindered by complex pathogenesis and a failure to clearly define the rate-limiting steps in disease progression. An alternative approach is to directly target the mutant gene product or a defined causative protein. Antisense oligonucleotides (ASOs) - with their diverse functionality, high target specificity, and relative ease of central nervous system (CNS) delivery - are uniquely positioned as potential therapies for neurological diseases. Here we review the development of ASOs for the treatment of inherited neurodegenerative diseases.
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Affiliation(s)
- Amber L Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, V5Z 4H4, Canada.
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173
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Southwell AL, Warby SC, Carroll JB, Doty CN, Skotte NH, Zhang W, Villanueva EB, Kovalik V, Xie Y, Pouladi MA, Collins JA, Yang XW, Franciosi S, Hayden MR. A fully humanized transgenic mouse model of Huntington disease. Hum Mol Genet 2012; 22:18-34. [PMID: 23001568 DOI: 10.1093/hmg/dds397] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Silencing the mutant huntingtin gene (muHTT) is a direct and simple therapeutic strategy for the treatment of Huntington disease (HD) in principle. However, targeting the HD mutation presents challenges because it is an expansion of a common genetic element (a CAG tract) that is found throughout the genome. Moreover, the HTT protein is important for neuronal health throughout life, and silencing strategies that also reduce the wild-type HTT allele may not be well tolerated during the long-term treatment of HD. Several HTT silencing strategies are in development that target genetic sites in HTT that are outside of the CAG expansion, including HD mutation-linked single-nucleotide polymorphisms and the HTT promoter. Preclinical testing of these genetic therapies has required the development of a new mouse model of HD that carries these human-specific genetic targets. To generate a fully humanized mouse model of HD, we have cross-bred BACHD and YAC18 on the Hdh(-/-) background. The resulting line, Hu97/18, is the first murine model of HD that fully genetically recapitulates human HD having two human HTT genes, no mouse Hdh genes and heterozygosity of the HD mutation. We find that Hu97/18 mice display many of the behavioral changes associated with HD including motor, psychiatric and cognitive deficits, as well as canonical neuropathological abnormalities. This mouse line will be useful for gaining additional insights into the disease mechanisms of HD as well as for testing genetic therapies targeting human HTT.
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Affiliation(s)
- Amber L Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
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174
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Tietjen I, Hovingh GK, Singaraja RR, Radomski C, Barhdadi A, McEwen J, Chan E, Mattice M, Legendre A, Franchini PL, Dubé MP, Kastelein JJP, Hayden MR. Segregation of LIPG, CETP, and GALNT2 mutations in Caucasian families with extremely high HDL cholesterol. PLoS One 2012; 7:e37437. [PMID: 22952570 PMCID: PMC3428317 DOI: 10.1371/journal.pone.0037437] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 04/23/2012] [Indexed: 11/28/2022] Open
Abstract
To date, few mutations are described to underlie highly-elevated HDLc levels in families. Here we sequenced the coding regions and adjacent sequence of the LIPG, CETP, and GALNT2 genes in 171 unrelated Dutch Caucasian probands with HDLc≥90th percentile and analyzed segregation of mutations with lipid phenotypes in family members. In these probands, mutations were most frequent in LIPG (12.9%) followed by GALNT2 (2.3%) and CETP (0.6%). A total of 6 of 10 mutations in these three genes were novel (60.0%), and mutations segregated with elevated HDLc in families. Interestingly, the LIPG mutations N396S and R476W, which usually result in elevated HDLc, were unexpectedly found in 6 probands with low HDLc (i.e., ≤10th percentile). However, 5 of these probands also carried mutations in ABCA1, LCAT, or LPL. Finally, no CETP and GALNT2 mutations were found in 136 unrelated probands with low HDLc. Taken together, we show that rare coding and splicing mutations in LIPG, CETP, and GALNT2 are enriched in persons with hyperalphalipoproteinemia and segregate with elevated HDLc in families. Moreover, LIPG mutations do not overcome low HDLc in individuals with ABCA1 and possibly LCAT and LPL mutations, indicating that LIPG affects HDLc levels downstream of these proteins.
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Affiliation(s)
| | - G. Kees Hovingh
- Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Roshni R. Singaraja
- Xenon Pharmaceuticals Inc., Burnaby, Canada
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | | | | | | | - Elden Chan
- Xenon Pharmaceuticals Inc., Burnaby, Canada
| | | | | | | | | | - John J. P. Kastelein
- Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
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175
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Brunham LR, Hayden MR. Personalized Medicine: Temper Expectations—Response. Science 2012. [DOI: 10.1126/science.337.6097.911-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Liam R. Brunham
- Departments of Medicine and Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia; and Translational Laboratory in Genetic Medicine, National University of Singapore and Association for Science Technology and Research (A-STAR), Singapore
| | - Michael R. Hayden
- Departments of Medicine and Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia; and Translational Laboratory in Genetic Medicine, National University of Singapore and Association for Science Technology and Research (A-STAR), Singapore
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176
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Semaka A, Balneaves LG, Hayden MR. "Grasping the grey": patient understanding and interpretation of an intermediate allele predictive test result for Huntington disease. J Genet Couns 2012; 22:200-17. [PMID: 22903792 DOI: 10.1007/s10897-012-9533-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 07/30/2012] [Indexed: 10/28/2022]
Abstract
Since the discovery of the genetic mutation underlying Huntington disease (HD) and the development of predictive testing, the genetics of HD has generally been described as straightforward; an individual receives either mutation-positive or negative predictive test results. However, in actuality, the genetics of HD is complex and a small proportion of individuals receive an unusual predictive test result called an intermediate allele (IA). Unlike mutation-positive or negative results, IAs confer uncertain clinical implications. While individuals with an IA will usually not develop HD, there remains an unknown risk for their children and future generations to develop the disorder. The purpose of this study was to explore how individuals understood and interpreted their IA result. Interviews were conducted with 29 individuals who received an IA result and 8 medical genetics service providers. Interviews were analyzed using the constant comparative method and the coding procedures of grounded theory. Many participants had difficulty "Grasping the Grey" (i.e. understanding and interpreting their IA results) and their family experience, beliefs, expectations, and genetic counseling influenced the degree of this struggle. The theoretical model developed informs clinical practice regarding IAs, ensuring that this unique subset of patients received appropriate education, support, and counseling.
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Affiliation(s)
- A Semaka
- Department of Medical Genetics, Centre for Molecular Medicine & Therapeutics, University of British Columbia, 950 West 28th Ave, Vancouver, BC V5Z 4H4, Canada.
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177
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Goldberg YP, Pimstone SN, Namdari R, Price N, Cohen C, Sherrington RP, Hayden MR. Human Mendelian pain disorders: a key to discovery and validation of novel analgesics. Clin Genet 2012; 82:367-73. [PMID: 22845492 DOI: 10.1111/j.1399-0004.2012.01942.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 07/03/2012] [Accepted: 07/23/2012] [Indexed: 12/21/2022]
Abstract
We have utilized a novel application of human genetics, illuminating the important role that rare genetic disorders can play in the development of novel drugs that may be of relevance for the treatment of both rare and common diseases. By studying a very rare Mendelian disorder of absent pain perception, congenital indifference to pain, we have defined Nav1.7 (endocded by SCN9A) as a critical and novel target for analgesic development. Strong human validation has emerged with SCN9A gain-of-function mutations causing inherited erythromelalgia (IEM) and paroxysmal extreme pain disorder, both Mendelian disorder of spontaneous or easily evoked pain. Furthermore, variations in the Nav1.7 channel also modulate pain perception in healthy subjects as well as in painful conditions such as osteoarthritis and Parkinson disease. On the basis of this, we have developed a novel compound (XEN402) that exhibits potent, voltage-dependent block of Nav1.7. In a small pilot study, we showed that XEN402 blocks Nav1.7 mediated pain associated with IEM thereby demonstrating the use of rare genetic disorders with mutant target channels as a novel approach to rapid proof-of-concept. Our approach underscores the critical role that human genetics can play by illuminating novel and critical pathways pertinent for drug discovery.
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Affiliation(s)
- Y P Goldberg
- Department of Clinical Development, Xenon Pharmaceuticals Inc, Burnaby, British Columbia, Canada.
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178
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Lee JH, Lee JM, Ramos EM, Gillis T, Mysore JS, Kishikawa S, Hadzi T, Hendricks AE, Hayden MR, Morrison PJ, Nance M, Ross CA, Margolis RL, Squitieri F, Gellera C, Gomez-Tortosa E, Ayuso C, Suchowersky O, Trent RJ, McCusker E, Novelletto A, Frontali M, Jones R, Ashizawa T, Frank S, Saint-Hilaire MH, Hersch SM, Rosas HD, Lucente D, Harrison MB, Zanko A, Abramson RK, Marder K, Sequeiros J, Landwehrmeyer GB, Shoulson I, Myers RH, MacDonald ME, Gusella JF. TAA repeat variation in the GRIK2 gene does not influence age at onset in Huntington's disease. Biochem Biophys Res Commun 2012; 424:404-8. [PMID: 22771793 PMCID: PMC3752397 DOI: 10.1016/j.bbrc.2012.06.120] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 06/25/2012] [Indexed: 11/29/2022]
Abstract
Huntington's disease is a neurodegenerative disorder caused by an expanded CAG trinucleotide repeat whose length is the major determinant of age at onset but remaining variation appears to be due in part to the effect of genetic modifiers. GRIK2, which encodes GluR6, a mediator of excitatory neurotransmission in the brain, has been suggested in several studies to be a modifier gene based upon a 3' untranslated region TAA trinucleotide repeat polymorphism. Prior to investing in detailed studies of the functional impact of this polymorphism, we sought to confirm its effect on age at onset in a much larger dataset than in previous investigations. We genotyped the HD CAG repeat and the GRIK2 TAA repeat in DNA samples from 2,911 Huntington's disease subjects with known age at onset, and tested for a potential modifier effect of GRIK2 using a variety of statistical approaches. Unlike previous reports, we detected no evidence of an influence of the GRIK2 TAA repeat polymorphism on age at motor onset. Similarly, the GRIK2 polymorphism did not show significant modifier effect on psychiatric and cognitive age at onset in HD. Comprehensive analytical methods applied to a much larger sample than in previous studies do not support a role for GRIK2 as a genetic modifier of age at onset of clinical symptoms in Huntington's disease.
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Affiliation(s)
- Ji-Hyun Lee
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA 02114, USA.
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179
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Ramos EM, Latourelle JC, Lee JH, Gillis T, Mysore JS, Squitieri F, Di Pardo A, Di Donato S, Hayden MR, Morrison PJ, Nance M, Ross CA, Margolis RL, Gomez-Tortosa E, Ayuso C, Suchowersky O, Trent RJ, McCusker E, Novelletto A, Frontali M, Jones R, Ashizawa T, Frank S, Saint-Hilaire MH, Hersch SM, Rosas HD, Lucente D, Harrison MB, Zanko A, Marder K, Gusella JF, Lee JM, Alonso I, Sequeiros J, Myers RH, MacDonald ME. Population stratification may bias analysis of PGC-1α as a modifier of age at Huntington disease motor onset. Hum Genet 2012; 131:1833-40. [PMID: 22825315 PMCID: PMC3492689 DOI: 10.1007/s00439-012-1205-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 07/11/2012] [Indexed: 11/26/2022]
Abstract
Huntington’s disease (HD) is an inherited neurodegenerative disorder characterized by motor, cognitive and behavioral disturbances, caused by the expansion of a CAG trinucleotide repeat in the HD gene. The CAG allele size is the major determinant of age at onset (AO) of motor symptoms, although the remaining variance in AO is highly heritable. The rs7665116 SNP in PPARGC1A, encoding the mitochondrial regulator PGC-1α, has been reported to be a significant modifier of AO in three European HD cohorts, perhaps due to affected cases from Italy. We attempted to replicate these findings in a large collection of (1,727) HD patient DNA samples of European origin. In the entire cohort, rs7665116 showed a significant effect in the dominant model (p value = 0.008) and the additive model (p value = 0.009). However, when examined by origin, cases of Southern European origin had an increased rs7665116 minor allele frequency (MAF), consistent with this being an ancestry-tagging SNP. The Southern European cases, despite similar mean CAG allele size, had a significantly older mean AO (p < 0.001), suggesting population-dependent phenotype stratification. When the generalized estimating equations models were adjusted for ancestry, the effect of the rs7665116 genotype on AO decreased dramatically. Our results do not support rs7665116 as a modifier of AO of motor symptoms, as we found evidence for a dramatic effect of phenotypic (AO) and genotypic (MAF) stratification among European cohorts that was not considered in previously reported association studies. A significantly older AO in Southern Europe may reflect population differences in genetic or environmental factors that warrant further investigation.
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Affiliation(s)
- Eliana Marisa Ramos
- Center for Human Genetic Research, Massachusetts General Hospital, Simches Research Building, Room 5414, 185 Cambridge Street, Boston, MA 02114 USA
- UnIGENe, IBMC, Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
| | - Jeanne C. Latourelle
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118 USA
| | - Ji-Hyun Lee
- Center for Human Genetic Research, Massachusetts General Hospital, Simches Research Building, Room 5414, 185 Cambridge Street, Boston, MA 02114 USA
| | - Tammy Gillis
- Center for Human Genetic Research, Massachusetts General Hospital, Simches Research Building, Room 5414, 185 Cambridge Street, Boston, MA 02114 USA
| | - Jayalakshmi S. Mysore
- Center for Human Genetic Research, Massachusetts General Hospital, Simches Research Building, Room 5414, 185 Cambridge Street, Boston, MA 02114 USA
| | - Ferdinando Squitieri
- Centre for Neurogenetics and Rare Diseases, IRCCS Neuromed, 86077 Pozzilli (IS), Italy
| | - Alba Di Pardo
- Centre for Neurogenetics and Rare Diseases, IRCCS Neuromed, 86077 Pozzilli (IS), Italy
| | - Stefano Di Donato
- Fondazione IRCCS Istituto Neurologico Carlo Besta, via Celoria 11 20133, Milan, Italy
| | - Michael R. Hayden
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z 4H4 Canada
| | - Patrick J. Morrison
- Regional Medical Genetics Centre, Belfast HSC Trust, Belfast, BT9 7AB UK
- University of Ulster, Cromore Road, Coleraine, BT52 15A UK
| | - Martha Nance
- Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN 55415 USA
| | - Christopher A. Ross
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD 21287 USA
| | - Russell L. Margolis
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD 21287 USA
| | | | - Carmen Ayuso
- Department of Genetics, IIS, Fundación Jiménez Diaz, CIBERER, 28040 Madrid, Spain
| | - Oksana Suchowersky
- Departments of Medicine and Medical Genetics, University of Alberta, Edmonton, AB T6G 2B7 Canada
| | - Ronald J. Trent
- Sydney Medical School, University of Sydney, Sydney, NSW 2006 Australia
| | - Elizabeth McCusker
- Department of Neurology, Westmead Hospital, Westmead Sydney, NSW 2145 Australia
| | | | - Marina Frontali
- Institute of Translational Pharmacology, CNR 00133 Rome, Italy
| | - Randi Jones
- Department of Neurology, Emory University, Atlanta, GA 30329 USA
| | - Tetsuo Ashizawa
- Department of Neurology, University of Florida, Gainesville, FL 32610 USA
| | - Samuel Frank
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118 USA
| | | | - Steven M. Hersch
- MIND, Massachusetts General Hospital, 114 16th Street, Charlestown, MA 02129 USA
| | - Herminia D. Rosas
- MIND, Massachusetts General Hospital, 114 16th Street, Charlestown, MA 02129 USA
| | - Diane Lucente
- Center for Human Genetic Research, Massachusetts General Hospital, Simches Research Building, Room 5414, 185 Cambridge Street, Boston, MA 02114 USA
| | | | - Andrea Zanko
- Department of Pediatrics, University of California, San Francisco, CA 94143 USA
| | - Karen Marder
- College of Physicians and Surgeons, Columbia University, New York, NY 10032 USA
| | - James F. Gusella
- Center for Human Genetic Research, Massachusetts General Hospital, Simches Research Building, Room 5414, 185 Cambridge Street, Boston, MA 02114 USA
- Harvard Medical School and Program in Medical and Population Genetics, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142 USA
| | - Jong-Min Lee
- Center for Human Genetic Research, Massachusetts General Hospital, Simches Research Building, Room 5414, 185 Cambridge Street, Boston, MA 02114 USA
- Harvard Medical School and Program in Medical and Population Genetics, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142 USA
| | - Isabel Alonso
- UnIGENe, IBMC, Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
- CGPP, IBMC, Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto, Portugal
| | - Jorge Sequeiros
- UnIGENe, IBMC, Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
- CGPP, IBMC, Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto, Portugal
| | - Richard H. Myers
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118 USA
| | - Marcy E. MacDonald
- Center for Human Genetic Research, Massachusetts General Hospital, Simches Research Building, Room 5414, 185 Cambridge Street, Boston, MA 02114 USA
- Harvard Medical School and Program in Medical and Population Genetics, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142 USA
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180
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Young FB, Franciosi S, Spreeuw A, Deng Y, Sanders S, Tam NCM, Huang K, Singaraja RR, Zhang W, Bissada N, Kay C, Hayden MR. Low levels of human HIP14 are sufficient to rescue neuropathological, behavioural, and enzymatic defects due to loss of murine HIP14 in Hip14-/- mice. PLoS One 2012; 7:e36315. [PMID: 22649491 PMCID: PMC3359340 DOI: 10.1371/journal.pone.0036315] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/02/2012] [Indexed: 11/25/2022] Open
Abstract
Huntingtin Interacting Protein 14 (HIP14) is a palmitoyl acyl transferase (PAT) that was first identified due to altered interaction with mutant huntingtin, the protein responsible for Huntington Disease (HD). HIP14 palmitoylates a specific set of neuronal substrates critical at the synapse, and downregulation of HIP14 by siRNA in vitro results in increased cell death in neurons. We previously reported that mice lacking murine Hip14 (Hip14-/-) share features of HD. In the current study, we have generated human HIP14 BAC transgenic mice and crossed them to the Hip14-/- model in order to confirm that the defects seen in Hip14-/- mice are in fact due to loss of Hip14. In addition, we sought to determine whether human HIP14 can provide functional compensation for loss of murine Hip14. We demonstrate that despite a relative low level of expression, as assessed via Western blot, BAC-derived human HIP14 compensates for deficits in neuropathology, behavior, and PAT enzyme function seen in the Hip14-/- model. Our findings yield important insights into HIP14 function in vivo.
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Affiliation(s)
- Fiona B. Young
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sonia Franciosi
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amanda Spreeuw
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yu Deng
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shaun Sanders
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Natalie C. M. Tam
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kun Huang
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Roshni R. Singaraja
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Weining Zhang
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nagat Bissada
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Chris Kay
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
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181
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Uribe V, Wong BK, Graham RK, Cusack CL, Skotte NH, Pouladi MA, Xie Y, Feinberg K, Ou Y, Ouyang Y, Deng Y, Franciosi S, Bissada N, Spreeuw A, Zhang W, Ehrnhoefer DE, Vaid K, Miller FD, Deshmukh M, Howland D, Hayden MR. Rescue from excitotoxicity and axonal degeneration accompanied by age-dependent behavioral and neuroanatomical alterations in caspase-6-deficient mice. Hum Mol Genet 2012; 21:1954-67. [PMID: 22262731 PMCID: PMC3315204 DOI: 10.1093/hmg/dds005] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 01/09/2012] [Indexed: 11/13/2022] Open
Abstract
Apoptosis, or programmed cell death, is a cellular pathway involved in normal cell turnover, developmental tissue remodeling, embryonic development, cellular homeostasis maintenance and chemical-induced cell death. Caspases are a family of intracellular proteases that play a key role in apoptosis. Aberrant activation of caspases has been implicated in human diseases. In particular, numerous findings implicate Caspase-6 (Casp6) in neurodegenerative diseases, including Alzheimer disease (AD) and Huntington disease (HD), highlighting the need for a deeper understanding of Casp6 biology and its role in brain development. The use of targeted caspase-deficient mice has been instrumental for studying the involvement of caspases in apoptosis. The goal of this study was to perform an in-depth neuroanatomical and behavioral characterization of constitutive Casp6-deficient (Casp6-/-) mice in order to understand the physiological function of Casp6 in brain development, structure and function. We demonstrate that Casp6-/- neurons are protected against excitotoxicity, nerve growth factor deprivation and myelin-induced axonal degeneration. Furthermore, Casp6-deficient mice show an age-dependent increase in cortical and striatal volume. In addition, these mice show a hypoactive phenotype and display learning deficits. The age-dependent behavioral and region-specific neuroanatomical changes observed in the Casp6-/- mice suggest that Casp6 deficiency has a more pronounced effect in brain regions that are involved in neurodegenerative diseases, such as the striatum in HD and the cortex in AD.
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Affiliation(s)
- Valeria Uribe
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Bibiana K.Y. Wong
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Rona K. Graham
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Corey L. Cusack
- Department of Cell and Developmental Biology and Neuroscience Center, University of North Carolina, Chapel Hill, NC27599-7250, USA
| | - Niels H. Skotte
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
- Department of Medical Genetics, Institute of Cellular and Molecular Medicine, University of Copenhagen, 2200 N Copenhagen, Denmark
| | - Mahmoud A. Pouladi
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Yuanyun Xie
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Konstantin Feinberg
- Developmental and Stem Cell Biology Group, Hospital for Sick Children, Toronto, OntarioM5G1L7, Canada
| | - Yimiao Ou
- Developmental and Stem Cell Biology Group, Hospital for Sick Children, Toronto, OntarioM5G1L7, Canada
| | | | - Yu Deng
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Sonia Franciosi
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Nagat Bissada
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Amanda Spreeuw
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Weining Zhang
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Dagmar E. Ehrnhoefer
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Kuljeet Vaid
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Freda D. Miller
- Developmental and Stem Cell Biology Group, Hospital for Sick Children, Toronto, OntarioM5G1L7, Canada
- Department of Molecular Genetics and
- Department of Physiology, University of Toronto, Toronto, OntarioM5G1X5, Canada
| | - Mohanish Deshmukh
- Department of Cell and Developmental Biology and Neuroscience Center, University of North Carolina, Chapel Hill, NC27599-7250, USA
| | | | - Michael R. Hayden
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
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182
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Young FB, Butland SL, Sanders SS, Sutton LM, Hayden MR. Putting proteins in their place: Palmitoylation in Huntington disease and other neuropsychiatric diseases. Prog Neurobiol 2012; 97:220-38. [DOI: 10.1016/j.pneurobio.2011.11.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 11/01/2011] [Accepted: 11/08/2011] [Indexed: 01/02/2023]
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183
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Kelly LE, Rieder M, van den Anker J, Malkin B, Ross C, Neely MN, Carleton B, Hayden MR, Madadi P, Koren G. More codeine fatalities after tonsillectomy in North American children. Pediatrics 2012; 129:e1343-7. [PMID: 22492761 DOI: 10.1542/peds.2011-2538] [Citation(s) in RCA: 299] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In 2009 we reported the fatal case of a toddler who had received codeine after adenotonsillectomy for obstructive sleep apnea syndrome. The child was an ultra-rapid metabolizer of cytochrome P4502D6 (CYP2D6). We now report 3 additional fatal or life-threatening cases from North America. In the 2 fatal cases, functional gene duplications encoding for CYP2D6 caused a significantly greater production of potent morphine from its parent drug, codeine. A severe case of respiratory depression in an extensive metabolizer is also noted. These cases demonstrate that analgesia with codeine or other opioids that use the CYP2D6 pathway after adenotonsillectomy may not be safe in young children with obstructive sleep apnea syndrome.
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Affiliation(s)
- Lauren E Kelly
- Schulich School of Medicine, University of Western Ontario, London, Canada
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184
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Affiliation(s)
- Alice K Hawkins
- Centre for Molecular Medicine and Therapeutics, 950 West 28th Ave, University of British Columbia, Child and Family Research Institute, Vancouver V5Z 4H4, BC, Canada.
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185
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Wijesekara N, Zhang LH, Kang MH, Abraham T, Bhattacharjee A, Warnock GL, Verchere CB, Hayden MR. miR-33a modulates ABCA1 expression, cholesterol accumulation, and insulin secretion in pancreatic islets. Diabetes 2012; 61:653-8. [PMID: 22315319 PMCID: PMC3282802 DOI: 10.2337/db11-0944] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Changes in cellular cholesterol affect insulin secretion, and β-cell-specific deletion or loss-of-function mutations in the cholesterol efflux transporter ATP-binding cassette transporter A1 (ABCA1) result in impaired glucose tolerance and β-cell dysfunction. Upregulation of ABCA1 expression may therefore be beneficial for the maintenance of normal islet function in diabetes. Studies suggest that microRNA-33a (miR-33a) expression inversely correlates with ABCA1 expression in hepatocytes and macrophages. We examined whether miR-33a regulates ABCA1 expression in pancreatic islets, thereby affecting cholesterol accumulation and insulin secretion. Adenoviral miR-33a overexpression in human or mouse islets reduced ABCA1 expression, decreased glucose-stimulated insulin secretion, and increased cholesterol levels. The miR-33a-induced reduction in insulin secretion was rescued by cholesterol depletion by methyl-β-cyclodextrin or mevastatin. Inhibition of miR-33a expression in apolipoprotein E knockout islets and ABCA1 overexpression in β-cell-specific ABCA1 knockout islets rescued normal insulin secretion and reduced islet cholesterol. These findings confirm the critical role of β-cell ABCA1 in islet cholesterol homeostasis and β-cell function and highlight modulation of β-cell miR-33a expression as a means to influence insulin secretion.
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Affiliation(s)
- Nadeeja Wijesekara
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lin-hua Zhang
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Martin H. Kang
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas Abraham
- Institute for Heart and Lung Health, St. Paul’s Hospital, Vancouver, British Columbia, Canada
| | - Alpana Bhattacharjee
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Garth L. Warnock
- Department of Surgery, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - C. Bruce Verchere
- Department of Surgery, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Corresponding author: Michael R. Hayden,
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186
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Bombard Y, Palin J, Friedman JM, Veenstra G, Creighton S, Bottorff JL, Hayden MR. Beyond the patient: the broader impact of genetic discrimination among individuals at risk of Huntington disease. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:217-26. [PMID: 22231990 DOI: 10.1002/ajmg.b.32016] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 12/07/2011] [Indexed: 11/07/2022]
Abstract
We aimed to address gaps in current understanding of the scope and impact of discrimination, by examining a cohort of individuals at-risk for Huntington disease (HD), to describe the prevalence of concern for oneself and one's family in multiple domains; strategies used to mitigate discrimination; and the extent to which concerns relate to experiences. We conducted a cross-sectional survey of 293 individuals at-risk for HD (80% response rate); 167 respondents were genetically tested and 66 were not. Fear of discrimination was widespread (86%), particularly in the insurance, family and social settings. Approximately half of concerned individuals experienced discrimination (40-62%, depending on genetic status). Concern was associated with "keeping quiet" about one's risk of HD or "taking action to avoid" discrimination. Importantly, concern was highly distressing for some respondents (21% for oneself; 32% for relatives). Overall, concerned respondents with high education levels, who discovered their family history at a younger age, and those who were mutation-positive were more likely to report experiences of discrimination than others who were concerned. Concerns were rarely attributed to genetic test results alone. Concern about genetic discrimination is frequent among individuals at-risk of HD and spans many settings. It influences behavioral patterns and can result in high levels of self-rated distress, highlighting the need for practice and policy interventions. © 2012 Wiley Periodicals, Inc.
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Affiliation(s)
- Yvonne Bombard
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
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187
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Kruit JK, Wijesekara N, Westwell-Roper C, Vanmierlo T, de Haan W, Bhattacharjee A, Tang R, Wellington CL, LütJohann D, Johnson JD, Brunham LR, Verchere CB, Hayden MR. Loss of both ABCA1 and ABCG1 results in increased disturbances in islet sterol homeostasis, inflammation, and impaired β-cell function. Diabetes 2012; 61:659-64. [PMID: 22315310 PMCID: PMC3282825 DOI: 10.2337/db11-1341] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cellular cholesterol homeostasis is important for normal β-cell function. Disruption of cholesterol transport by decreased function of the ATP-binding cassette (ABC) transporter ABCA1 results in impaired insulin secretion. Mice lacking β-cell ABCA1 have increased islet expression of ABCG1, another cholesterol transporter implicated in β-cell function. To determine whether ABCA1 and ABCG1 have complementary roles in β-cells, mice lacking ABCG1 and β-cell ABCA1 were generated and glucose tolerance, islet sterol levels, and β-cell function were assessed. Lack of both ABCG1 and β-cell ABCA1 resulted in increased fasting glucose levels and a greater impairment in glucose tolerance compared with either ABCG1 deletion or loss of ABCA1 in β-cells alone. In addition, glucose-stimulated insulin secretion was decreased and sterol accumulation increased in islets lacking both transporters compared with those isolated from knockout mice with each gene alone. Combined deficiency of ABCA1 and ABCG1 also resulted in significant islet inflammation as indicated by increased expression of interleukin-1β and macrophage infiltration. Thus, lack of both ABCA1 and ABCG1 induces greater defects in β-cell function than deficiency of either transporter individually. These data suggest that ABCA1 and ABCG1 each make complimentary and important contributions to β-cell function by maintaining islet cholesterol homeostasis in vivo.
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Affiliation(s)
- Janine K. Kruit
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nadeeja Wijesekara
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Clara Westwell-Roper
- Department of Pathology and Laboratory Medicine, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tim Vanmierlo
- Laboratory for Special Lipid Diagnostics, Institute of Clinical Chemistry and Clinical Pharmacology, University Clinics of Bonn, Bonn, Germany
| | - Willeke de Haan
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alpana Bhattacharjee
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Renmei Tang
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Cheryl L. Wellington
- Department of Pathology and Laboratory Medicine, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dieter LütJohann
- Laboratory for Special Lipid Diagnostics, Institute of Clinical Chemistry and Clinical Pharmacology, University Clinics of Bonn, Bonn, Germany
| | - James D. Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Liam R. Brunham
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - C. Bruce Verchere
- Departments of Surgery and Pathology and Laboratory Medicine, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
- Corresponding author: Michael R. Hayden,
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188
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Pouladi MA, Stanek LM, Xie Y, Franciosi S, Southwell AL, Deng Y, Butland S, Zhang W, Cheng SH, Shihabuddin LS, Hayden MR. Marked differences in neurochemistry and aggregates despite similar behavioural and neuropathological features of Huntington disease in the full-length BACHD and YAC128 mice. Hum Mol Genet 2012; 21:2219-32. [PMID: 22328089 DOI: 10.1093/hmg/dds037] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The development of animal models of Huntington disease (HD) has enabled studies that help define the molecular aberrations underlying the disease. The BACHD and YAC128 transgenic mouse models of HD harbor a full-length mutant huntingtin (mHTT) and recapitulate many of the behavioural and neuropathological features of the human condition. Here, we demonstrate that while BACHD and YAC128 animals exhibit similar deficits in motor learning and coordination, depressive-like symptoms, striatal volume loss and forebrain weight loss, they show obvious differences in key features characteristic of HD. While YAC128 mice exhibit significant and widespread accumulation of mHTT striatal aggregates, these mHTT aggregates are absent in BACHD mice. Furthermore, the levels of several striatally enriched mRNA for genes, such as DARPP-32, enkephalin, dopamine receptors D1 and D2 and cannabinoid receptor 1, are significantly decreased in YAC128 but not BACHD mice. These findings may reflect sequence differences in the human mHTT transgenes harboured by the BACHD and YAC128 mice, including both single nucleotide polymorphisms as well as differences in the nature of CAA interruptions of the CAG tract. Our findings highlight a similar profile of HD-like behavioural and neuropathological deficits and illuminate differences that inform the use of distinct endpoints in trials of therapeutic agents in the YAC128 and BACHD mice.
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Affiliation(s)
- Mahmoud A Pouladi
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, and Child and Family Research Institute, Vancouver, BC, Canada
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189
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Lee JM, Ramos EM, Lee JH, Gillis T, Mysore JS, Hayden MR, Warby SC, Morrison P, Nance M, Ross CA, Margolis RL, Squitieri F, Orobello S, Di Donato S, Gomez-Tortosa E, Ayuso C, Suchowersky O, Trent RJA, McCusker E, Novelletto A, Frontali M, Jones R, Ashizawa T, Frank S, Saint-Hilaire MH, Hersch SM, Rosas HD, Lucente D, Harrison MB, Zanko A, Abramson RK, Marder K, Sequeiros J, Paulsen JS, Landwehrmeyer GB, Myers RH, MacDonald ME, Gusella JF. CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion. Neurology 2012; 78:690-5. [PMID: 22323755 DOI: 10.1212/wnl.0b013e318249f683] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs. METHODS We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression. RESULTS An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a well-behaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele. CONCLUSIONS Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors.
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Affiliation(s)
- J-M Lee
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, USA
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190
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Graham RK, Deng Y, Pouladi MA, Vaid K, Ehrnhoefer D, Southwell AL, Bissada N, Franciosi S, Hayden MR. Caspase-6-Resistant Mutant Huntingtin Does not Rescue the Toxic Effects of Caspase-Cleavable Mutant Huntingtin in vivo. J Huntingtons Dis 2012; 1:243-60. [DOI: 10.3233/jhd-120038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Rona K. Graham
- Research Center on Aging, Department of Physiology and Biophysics, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Yu Deng
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Mahmoud A. Pouladi
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Republic of Singapore
- Department of Medicine, National University of Singapore, Singapore, Republic of Singapore
| | - Kuljeet Vaid
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Dagmar Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Amber L. Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Nagat Bissada
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Sonia Franciosi
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
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Lam J, Kelly L, Ciszkowski C, Landsmeer MLA, Nauta M, Carleton BC, Hayden MR, Madadi P, Koren G. Central nervous system depression of neonates breastfed by mothers receiving oxycodone for postpartum analgesia. J Pediatr 2012; 160:33-7.e2. [PMID: 21880331 DOI: 10.1016/j.jpeds.2011.06.050] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 06/02/2011] [Accepted: 06/29/2011] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To quantify the incidence of central nervous system (CNS) depression in neonates breastfed by mothers medicated with oxycodone as compared with neonates whose breastfeeding mothers used codeine or acetaminophen only. STUDY DESIGN We retrospectively compared 3 cohorts in 533 breastfeeding mother-infant pairs exposed to oxycodone (n = 139), codeine (n = 210), or acetaminophen only (n = 184). Standardized questionnaires were administered to mothers during the postpartum period to identify maternal and neonatal health outcomes temporally related to analgesia exposure. RESULTS Maternal exposure to oxycodone during breastfeeding was associated with a 20.1% rate of infant CNS depression (28/139) compared with 0.5% in the acetaminophen group (1/184; P < .0001; OR, 46.16; 95% CI, 6.2-344.2) and 16.7% in the codeine group (35/210; P > .05; OR, 0.79; 95% CI, 0.46-1.38). Mothers of neonates with symptoms in the oxycodone and codeine cohorts took significantly higher doses of medication compared with mothers of infants with no symptoms in the same cohorts (P = .0005 oxycodone; median, 0.4 mg/kg/day; range, 0.03-4.06 mg/kg/day versus median, 0.15 mg/kg/day; range, 0.02-2.25 mg/kg/day; codeine P < .001; median, 1.4 mg/kg/day; range, 0.7-10.5 mg/kg/day versus 0.9 mg/kg/day; range, 0.18-5.8 mg/kg/day). Mothers were significantly more likely to experience sedative adverse effects from oxycodone as compared with codeine (P < .0001; OR, 17.62; 95% CI, 9.95-31.21). CONCLUSION Oxycodone is not a safer alternative to codeine in breastfed infants.
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Affiliation(s)
- Jessica Lam
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
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192
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Kruit JK, Wijesekara N, Fox JEM, Dai XQ, Brunham LR, Searle GJ, Morgan GP, Costin AJ, Tang R, Bhattacharjee A, Johnson JD, Light PE, Marsh BJ, MacDonald PE, Verchere CB, Hayden MR. Islet cholesterol accumulation due to loss of ABCA1 leads to impaired exocytosis of insulin granules. Diabetes 2011; 60:3186-96. [PMID: 21998401 PMCID: PMC3219942 DOI: 10.2337/db11-0081] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE The ATP-binding cassette transporter A1 (ABCA1) is essential for normal insulin secretion from β-cells. The aim of this study was to elucidate the mechanisms underlying the impaired insulin secretion in islets lacking β-cell ABCA1. RESEARCH DESIGN AND METHODS Calcium imaging, patch clamp, and membrane capacitance were used to assess the effect of ABCA1 deficiency on calcium flux, ion channel function, and exocytosis in islet cells. Electron microscopy was used to analyze β-cell ultrastructure. The quantity and distribution of proteins involved in insulin-granule exocytosis were also investigated. RESULTS We show that a lack of β-cell ABCA1 results in impaired depolarization-induced exocytotic fusion of insulin granules. We observed disturbances in membrane microdomain organization and Golgi and insulin granule morphology in β-cells as well as elevated fasting plasma proinsulin levels in mice in the absence of β-cell ABCA1. Acute cholesterol depletion rescued the exocytotic defect in β-cells lacking ABCA1, indicating that elevated islet cholesterol accumulation directly impairs granule fusion and insulin secretion. CONCLUSIONS Our data highlight a crucial role of ABCA1 and cellular cholesterol in β-cells that is necessary for regulated insulin granule fusion events. These data suggest that abnormalities of cholesterol metabolism may contribute to the impaired β-cell function in diabetes.
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Affiliation(s)
- Janine K. Kruit
- Departments of Medical Genetics, Centre for Molecular Medicine, and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nadeeja Wijesekara
- Departments of Medical Genetics, Centre for Molecular Medicine, and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jocelyn E. Manning Fox
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Xiao-Qing Dai
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Liam R. Brunham
- Departments of Medical Genetics, Centre for Molecular Medicine, and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gavin J. Searle
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Garry P. Morgan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Adam J. Costin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Renmei Tang
- Departments of Medical Genetics, Centre for Molecular Medicine, and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alpana Bhattacharjee
- Departments of Medical Genetics, Centre for Molecular Medicine, and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - James D. Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Peter E. Light
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Brad J. Marsh
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Patrick E. MacDonald
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - C. Bruce Verchere
- Departments of Pathology & Laboratory Medicine and Surgery, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Departments of Medical Genetics, Centre for Molecular Medicine, and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Corresponding author: Michael R. Hayden,
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193
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Graham RK, Ehrnhoefer DE, Hayden MR. Caspase-6 and neurodegeneration. Trends Neurosci 2011; 34:646-56. [DOI: 10.1016/j.tins.2011.09.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 09/02/2011] [Accepted: 09/13/2011] [Indexed: 01/10/2023]
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194
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Ehrnhoefer DE, Skotte NH, Savill J, Nguyen YTN, Ladha S, Cao LP, Dullaghan E, Hayden MR. A quantitative method for the specific assessment of caspase-6 activity in cell culture. PLoS One 2011; 6:e27680. [PMID: 22140457 PMCID: PMC3226564 DOI: 10.1371/journal.pone.0027680] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 10/21/2011] [Indexed: 01/04/2023] Open
Abstract
Aberrant activation of caspase-6 has recently emerged as a major contributor to the pathogeneses of neurodegenerative disorders such as Alzheimer's and Huntington disease. Commercially available assays to measure caspase-6 activity commonly use the VEID peptide as a substrate. However these methods are not well suited to specifically assess caspase-6 activity in the presence of other, confounding protease activities, as often encountered in cell and tissue samples. Here we report the development of a method that overcomes this limitation by using a protein substrate, lamin A, which is highly specific for caspase-6 cleavage at amino acid 230. Using a neo-epitope antibody against cleaved lamin A, we developed an electrochemiluminescence-based ELISA assay that is suitable to specifically detect and quantify caspase-6 activity in highly apoptotic cell extracts. The method is more sensitive than VEID-based assays and can be adapted to a high-content imaging platform for high-throughput screening. This method should be useful to screen for and characterize caspase-6 inhibitor compounds and other interventions to decrease intracellular caspase-6 activity for applications in neurodegenerative disorders.
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Affiliation(s)
- Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, CFRI, University of British Columbia, Vancouver, British Columbia, Canada
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195
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Ketelaar ME, Hofstra RMW, Hayden MR. What monozygotic twins discordant for phenotype illustrate about mechanisms influencing genetic forms of neurodegeneration. Clin Genet 2011; 81:325-33. [DOI: 10.1111/j.1399-0004.2011.01795.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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196
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Ehrnhoefer DE, Wong BKY, Hayden MR. Convergent pathogenic pathways in Alzheimer's and Huntington's diseases: shared targets for drug development. Nat Rev Drug Discov 2011; 10:853-67. [PMID: 22015920 DOI: 10.1038/nrd3556] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurodegenerative diseases, exemplified by Alzheimer's disease and Huntington's disease, are characterized by progressive neuropsychiatric dysfunction and loss of specific neuronal subtypes. Although there are differences in the exact sites of pathology, and the clinical profiles of these two conditions only partially overlap, considerable similarities in disease mechanisms and pathogenic pathways can be observed. These shared mechanisms raise the possibility of exploiting common therapeutic targets for drug development. As Huntington's disease has a monogenic cause, it is possible to accurately identify individuals who carry the Huntington's disease mutation but do not yet manifest symptoms. These individuals could act as a model for Alzheimer's disease to test therapeutic interventions that target shared pathogenic pathways.
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Affiliation(s)
- Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, 950 West 28th Avenue, Vancouver, British Columbia V5Z 4H4, Canada
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197
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Singaraja RR, Huang K, Sanders SS, Milnerwood AJ, Hines R, Lerch JP, Franciosi S, Drisdel RC, Vaid K, Young FB, Doty C, Wan J, Bissada N, Henkelman RM, Green WN, Davis NG, Raymond LA, Hayden MR. Altered palmitoylation and neuropathological deficits in mice lacking HIP14. Hum Mol Genet 2011; 20:3899-909. [PMID: 21775500 PMCID: PMC3177655 DOI: 10.1093/hmg/ddr308] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 07/02/2011] [Accepted: 07/11/2011] [Indexed: 02/02/2023] Open
Abstract
Huntingtin interacting protein 14 (HIP14, ZDHHC17) is a huntingtin (HTT) interacting protein with palmitoyl transferase activity. In order to interrogate the function of Hip14, we generated mice with disruption in their Hip14 gene. Hip14-/- mice displayed behavioral, biochemical and neuropathological defects that are reminiscent of Huntington disease (HD). Palmitoylation of other HIP14 substrates, but not Htt, was reduced in the Hip14-/- mice. Hip14 is dysfunctional in the presence of mutant htt in the YAC128 mouse model of HD, suggesting that altered palmitoylation mediated by HIP14 may contribute to HD.
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Affiliation(s)
- Roshni R. Singaraja
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
| | - Kun Huang
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
| | - Shaun S. Sanders
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
| | | | - Rochelle Hines
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Jason P. Lerch
- The Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada
| | - Sonia Franciosi
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
| | | | - Kuljeet Vaid
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
| | - Fiona B. Young
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
| | - Crystal Doty
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
| | - Junmei Wan
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Nagat Bissada
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
| | - R. Mark Henkelman
- The Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada
| | - William N. Green
- Department of Neurobiology, University of Chicago, Chicago, IL, USA and
| | - Nicholas G. Davis
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Lynn A. Raymond
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics and Child and Family Research Institute and
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198
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Abstract
Hyperphosphatemia is a major risk factor for cardiovascular disease, abnormalities of mineral metabolism and bone disease, and the progression of renal insufficiency in patients with chronic renal disease. In early renal disease, serum phosphate levels are maintained within the 'normal laboratory range' by compensatory increases in phosphaturic hormones such as fibroblast growth factor-23 (FGF-23). An important co-factor for FGF-23 is Klotho; a deficiency in Klotho plays an important role in the pathogenesis of hyperphosphatemia, renal tubulointerstitial disease, and parathyroid and bone abnormalities. Clinical hyperphosphatemia occurs when these phosphaturic mechanisms cannot counterbalance nephron loss. Hyperphosphatemia is associated with calcific uremic arteriolopathy and uremic cardiomyopathy, which may explain, in part, the epidemiologic connections between phosphate excess and cardiovascular disease. However, no clinical trials have been conducted to establish a causal relationship, and large, randomized trials with hard endpoints are urgently needed to prove or disprove the benefits and risks of therapy. In summary, hyperphosphatemia accelerates renal tubulointerstitial disease, renal osteodystrophy, as well as cardiovascular disease, and it is an important mortality risk factor in patients with chronic kidney disease.
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Affiliation(s)
- Deepashree Gupta
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
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199
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Carroll JB, Warby SC, Southwell AL, Doty CN, Greenlee S, Skotte N, Hung G, Bennett CF, Freier SM, Hayden MR. Potent and selective antisense oligonucleotides targeting single-nucleotide polymorphisms in the Huntington disease gene / allele-specific silencing of mutant huntingtin. Mol Ther 2011; 19:2178-85. [PMID: 21971427 DOI: 10.1038/mt.2011.201] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Huntington disease (HD) is an autosomal dominant neurodegenerative disorder caused by CAG-expansion in the huntingtin gene (HTT) that results in a toxic gain of function in the mutant huntingtin protein (mHTT). Reducing the expression of mHTT is therefore an attractive therapy for HD. However, wild-type HTT protein is essential for development and has critical roles in maintaining neuronal health. Therapies for HD that reduce wild-type HTT may therefore generate unintended negative consequences. We have identified single-nucleotide polymorphism (SNP) targets in the human HD population for the disease-specific targeting of the HTT gene. Using primary cells from patients with HD and the transgenic YAC18 and BACHD mouse lines, we developed antisense oligonucleotide (ASO) molecules that potently and selectively silence mHTT at both exonic and intronic SNP sites. Modification of these ASOs with S-constrained-ethyl (cET) motifs significantly improves potency while maintaining allele selectively in vitro. The developed ASO is potent and selective for mHTT in vivo after delivery to the mouse brain. We demonstrate that potent and selective allele-specific knockdown of the mHTT protein can be achieved at therapeutically relevant SNP sites using ASOs in vitro and in vivo.
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Affiliation(s)
- Jeffrey B Carroll
- Program in Neuroscience, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
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200
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Visscher H, Ross CJD, Rassekh SR, Barhdadi A, Dubé MP, Al-Saloos H, Sandor GS, Caron HN, van Dalen EC, Kremer LC, van der Pal HJ, Brown AMK, Rogers PC, Phillips MS, Rieder MJ, Carleton BC, Hayden MR. Pharmacogenomic prediction of anthracycline-induced cardiotoxicity in children. J Clin Oncol 2011; 30:1422-8. [PMID: 21900104 DOI: 10.1200/jco.2010.34.3467] [Citation(s) in RCA: 289] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Anthracycline-induced cardiotoxicity (ACT) is a serious adverse drug reaction limiting anthracycline use and causing substantial morbidity and mortality. Our aim was to identify genetic variants associated with ACT in patients treated for childhood cancer. PATIENTS AND METHODS We carried out a study of 2,977 single-nucleotide polymorphisms (SNPs) in 220 key drug biotransformation genes in a discovery cohort of 156 anthracycline-treated children from British Columbia, with replication in a second cohort of 188 children from across Canada and further replication of the top SNP in a third cohort of 96 patients from Amsterdam, the Netherlands. RESULTS We identified a highly significant association of a synonymous coding variant rs7853758 (L461L) within the SLC28A3 gene with ACT (odds ratio, 0.35; P = 1.8 × 10(-5) for all cohorts combined). Additional associations (P < .01) with risk and protective variants in other genes including SLC28A1 and several adenosine triphosphate-binding cassette transporters (ABCB1, ABCB4, and ABCC1) were present. We further explored combining multiple variants into a single-prediction model together with clinical risk factors and classification of patients into three risk groups. In the high-risk group, 75% of patients were accurately predicted to develop ACT, with 36% developing this within the first year alone, whereas in the low-risk group, 96% of patients were accurately predicted not to develop ACT. CONCLUSION We have identified multiple genetic variants in SLC28A3 and other genes associated with ACT. Combined with clinical risk factors, genetic risk profiling might be used to identify high-risk patients who can then be provided with safer treatment options.
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Affiliation(s)
- Henk Visscher
- University of British Columbia, Vancouver, British Columbia
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