151
|
Tiira K, Hakosalo O, Kareinen L, Thomas A, Hielm-Björkman A, Escriou C, Arnold P, Lohi H. Environmental effects on compulsive tail chasing in dogs. PLoS One 2012; 7:e41684. [PMID: 22844513 PMCID: PMC3406045 DOI: 10.1371/journal.pone.0041684] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [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: 02/29/2012] [Accepted: 06/24/2012] [Indexed: 11/18/2022] Open
Abstract
Obsessive Compulsive Disorder (OCD) is a neuropsychiatric disorder observed both in humans and animals. Examples of Canine Compulsive Disorder (CD) include excessive tail chasing (TC), light/shadow chasing and flank sucking. We performed a questionnaire survey to investigate the characteristics of compulsive (TC) and its possible associations with environmental correlates and personality in a pet population of 368 dogs from four dog breeds. We observed an early onset of TC at 3–6 months of age and a large variation in TC frequency in all breeds, with an overrepresentation of milder cases. Almost half of the TC dogs showed lowered responsiveness during bouts and displayed also other types of compulsions more often than the controls. Interestingly, dogs that received dietary supplements, especially vitamins and minerals, expressed less TC compared to dogs that did not receive any supplements. Neutered females had less TC, suggesting an influence of ovarian hormones on TC. Tail chasers were shyer and had separated earlier from their mothers than the controls. Finally, our genetic study did not find an association between TC and CDH2, a locus previously associated with the canine flank sucking compulsion. In conclusion, the early-onset and the variable nature of the repetitive behaviour, which is affected by environmental factors such as micronutrients, neutering and maternal care, share several similar components between canine and human compulsions and supports canine TC as a model for human OCD.
Collapse
Affiliation(s)
- Katriina Tiira
- Research Programs Unit, Molecular Medicine, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- The Folkhälsan Research Center, Helsinki, Finland
| | - Osmo Hakosalo
- Research Programs Unit, Molecular Medicine, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- The Folkhälsan Research Center, Helsinki, Finland
| | - Lauri Kareinen
- Research Programs Unit, Molecular Medicine, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- The Folkhälsan Research Center, Helsinki, Finland
| | - Anne Thomas
- Antagene, Animal Genetics Laboratory, Lyon, France
| | - Anna Hielm-Björkman
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
| | | | - Paul Arnold
- Program in Genetics and Genomic Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Hannes Lohi
- Research Programs Unit, Molecular Medicine, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- The Folkhälsan Research Center, Helsinki, Finland
- * E-mail:
| |
Collapse
|
152
|
Kyöstilä K, Cizinauskas S, Seppälä EH, Suhonen E, Jeserevics J, Sukura A, Syrjä P, Lohi H. A SEL1L mutation links a canine progressive early-onset cerebellar ataxia to the endoplasmic reticulum-associated protein degradation (ERAD) machinery. PLoS Genet 2012; 8:e1002759. [PMID: 22719266 PMCID: PMC3375262 DOI: 10.1371/journal.pgen.1002759] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [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: 11/15/2011] [Accepted: 04/30/2012] [Indexed: 11/23/2022] Open
Abstract
Inherited ataxias are characterized by degeneration of the cerebellar structures, which results in progressive motor incoordination. Hereditary ataxias occur in many species, including humans and dogs. Several mutations have been found in humans, but the genetic background has remained elusive in dogs. The Finnish Hound suffers from an early-onset progressive cerebellar ataxia. We have performed clinical, pathological, and genetic studies to describe the disease phenotype and to identify its genetic cause. Neurological examinations on ten affected dogs revealed rapidly progressing generalized cerebellar ataxia, tremors, and failure to thrive. Clinical signs were present by the age of 3 months, and cerebellar shrinkage was detectable through MRI. Pathological and histological examinations indicated cerebellum-restricted neurodegeneration. Marked loss of Purkinje cells was detected in the cerebellar cortex with secondary changes in other cortical layers. A genome-wide association study in a cohort of 31 dogs mapped the ataxia gene to a 1.5 Mb locus on canine chromosome 8 (praw = 1.1×10−7, pgenome = 7.5×10−4). Sequencing of a functional candidate gene, sel-1 suppressor of lin-12-like (SEL1L), revealed a homozygous missense mutation, c.1972T>C; p.Ser658Pro, in a highly conserved protein domain. The mutation segregated fully in the recessive pedigree, and a 10% carrier frequency was indicated in a population cohort. SEL1L is a component of the endoplasmic reticulum (ER)–associated protein degradation (ERAD) machinery and has not been previously associated to inherited ataxias. Dysfunctional protein degradation is known to cause ER stress, and we found a significant increase in expression of nine ER stress responsive genes in the cerebellar cortex of affected dogs, supporting the pathogenicity of the mutation. Our study describes the first early-onset neurodegenerative ataxia mutation in dogs, establishes an ERAD–mediated neurodegenerative disease model, and proposes SEL1L as a new candidate gene in progressive childhood ataxias. Furthermore, our results have enabled the development of a genetic test for breeders. Hereditary ataxias are a heterogeneous group of rare disorders characterized by progressive cerebellar neurodegeneration. Several causative mutations have been identified in various forms of human ataxias. In addition to humans, inherited ataxias have been described in several other species, including the domestic dog. In this study, we have studied the clinical and genetic properties of cerebellar ataxia in the Finnish Hound dog breed. The breed suffers from a progressive ataxia that has an early onset before the age of 3 months. Affected puppies have difficulties in coordinating their movements and balance, and have to be euthanized due to rapidly worsening symptoms. Our pedigree analysis suggested an autosomal recessive mode of inheritance, which was confirmed by identifying a homozygous mutation in the SEL1L gene through genome-wide association and linkage analyses. The SEL1L protein functions in a protein quality control pathway that targets misfolded proteins to degradation in the endoplasmic reticulum. Mutations in the SEL1L gene have not been previously found in ataxias. Our study indicates SEL1L as a novel candidate gene for human childhood ataxias, establishes a large animal model to investigate mechanisms of cerebellar neurodegeneration, and enables carrier screening for breeding purposes.
Collapse
Affiliation(s)
- Kaisa Kyöstilä
- Department of Medical Genetics, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- Department of Molecular Genetics, Folkhälsan Institute of Genetics, Helsinki, Finland
| | | | - Eija H. Seppälä
- Department of Medical Genetics, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- Department of Molecular Genetics, Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Esko Suhonen
- Small Animal Clinic Kontiolahti, Kontiolahti, Finland
| | | | - Antti Sukura
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Pernilla Syrjä
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Hannes Lohi
- Department of Medical Genetics, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- Department of Molecular Genetics, Folkhälsan Institute of Genetics, Helsinki, Finland
- * E-mail:
| |
Collapse
|
153
|
Girard JM, Stone SSD, Lohi H, Blaszykowski C, Teixeira C, Turnbull J, Wang A, Draginov A, Wang P, Zhao XC, Ackerley CA, Frankland PW, Minassian BA. Phosphorylation prevents polyglucosan transport in Lafora disease. Neurology 2012; 79:100-2. [PMID: 22622857 DOI: 10.1212/wnl.0b013e31825dcdac] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [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] Open
Affiliation(s)
- Jean-Marie Girard
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
154
|
Hasiwa N, Bailey J, Clausing P, Daneshian M, Eileraas M, Farkas S, Gyertyán I, Hubrecht R, Kobel W, Krummenacher G, Leist M, Lohi H, Miklósi A, Ohl F, Olejniczak K, Schmitt G, Sinnett-Smith P, Smith D, Wagner K, Yager JD, Zurlo J, Hartung T. Critical evaluation of the use of dogs in biomedical research and testing in Europe. ALTEX 2012; 28:326-40. [PMID: 22130483 DOI: 10.14573/altex.2011.4.326] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Dogs are sometimes referred to as "man's best friend" and with the increase in urbanization and lifestyle changes, dogs are seen by their owners as family members. Society expresses specific concerns about the experimental use of dogs, as they are sometimes perceived to have a special status for humans. This may appear somewhat conflicting with the idea that the intrinsic value of all animals is the same, and that also several other animal species are used in biomedical research and toxicology. This aspect and many others are discussed in an introductory chapter dealing with ethical considerations on the use of dogs as laboratory animals. The report gives an overview on the use of dogs in biomedical research, safety assessment and the drug developmental process and reflects the discussion on the use of dogs as second (non-rodent)species in toxicity testing. Approximately 20,000 dogs are used in scientific procedures in Europe every year, and their distinct genetic, physiological and behavioral characteristics may support their use as models for e.g. behavioral analysis and genetic research. Advances in the 3Rs (Replacement, Reduction and Refinement of experiments using dogs) are described, potential opportunities are discussed and recommendations for further progress in this area are made.
Collapse
Affiliation(s)
- Nina Hasiwa
- Centre for Alternatives to Animal Testing, Europe, University of Konstanz, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
155
|
Seppälä EH, Koskinen LLE, Gulløv CH, Jokinen P, Karlskov-Mortensen P, Bergamasco L, Baranowska Körberg I, Cizinauskas S, Oberbauer AM, Berendt M, Fredholm M, Lohi H. Identification of a novel idiopathic epilepsy locus in Belgian Shepherd dogs. PLoS One 2012; 7:e33549. [PMID: 22457775 PMCID: PMC3311644 DOI: 10.1371/journal.pone.0033549] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [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: 11/03/2011] [Accepted: 02/11/2012] [Indexed: 01/19/2023] Open
Abstract
Epilepsy is the most common neurological disorder in dogs, with an incidence ranging from 0.5% to up to 20% in particular breeds. Canine epilepsy can be etiologically defined as idiopathic or symptomatic. Epileptic seizures may be classified as focal with or without secondary generalization, or as primary generalized. Nine genes have been identified for symptomatic (storage diseases) and one for idiopathic epilepsy in different breeds. However, the genetic background of common canine epilepsies remains unknown. We have studied the clinical and genetic background of epilepsy in Belgian Shepherds. We collected 159 cases and 148 controls and confirmed the presence of epilepsy through epilepsy questionnaires and clinical examinations. The MRI was normal while interictal EEG revealed abnormalities and variable foci in the clinically examined affected dogs. A genome-wide association study using Affymetrix 50K SNP arrays in 40 cases and 44 controls mapped the epilepsy locus on CFA37, which was replicated in an independent cohort (81 cases and 88 controls; combined p = 9.70×10−10, OR = 3.3). Fine mapping study defined a ∼1 Mb region including 12 genes of which none are known epilepsy genes or encode ion channels. Exonic sequencing was performed for two candidate genes, KLF7 and ADAM23. No variation was found in KLF7 but a highly-associated non-synonymous variant, G1203A (R387H) was present in the ADAM23 gene (p = 3.7×10−8, OR = 3.9 for homozygosity). Homozygosity for a two-SNP haplotype within the ADAM23 gene conferred the highest risk for epilepsy (p = 6.28×10−11, OR = 7.4). ADAM23 interacts with known epilepsy proteins LGI1 and LGI2. However, our data suggests that the ADAM23 variant is a polymorphism and we have initiated a targeted re-sequencing study across the locus to identify the causative mutation. It would establish the affected breed as a novel therapeutic model, help to develop a DNA test for breeding purposes and introduce a novel candidate gene for human idiopathic epilepsies.
Collapse
Affiliation(s)
- Eija H. Seppälä
- Research Programs Unit, Molecular Medicine, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences and Department of Medical Genetics, University of Helsinki, Helsinki, Finland
- Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Lotta L. E. Koskinen
- Research Programs Unit, Molecular Medicine, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences and Department of Medical Genetics, University of Helsinki, Helsinki, Finland
- Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Christina H. Gulløv
- Department of Small Animal Clinical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Päivi Jokinen
- Research Programs Unit, Molecular Medicine, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences and Department of Medical Genetics, University of Helsinki, Helsinki, Finland
- Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Peter Karlskov-Mortensen
- Department of Basic Animal and Veterinary Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Luciana Bergamasco
- College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America
| | | | | | - Anita M. Oberbauer
- Department of Animal Science, University of California Davis, Davis, California, United States of America
| | - Mette Berendt
- Department of Small Animal Clinical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Merete Fredholm
- Department of Basic Animal and Veterinary Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hannes Lohi
- Research Programs Unit, Molecular Medicine, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences and Department of Medical Genetics, University of Helsinki, Helsinki, Finland
- Folkhälsan Institute of Genetics, Helsinki, Finland
- * E-mail:
| |
Collapse
|
156
|
Abstract
Doberman hepatitis (DH) is associated with homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 indicating a role for the immune system in the development of the disease. The dog leucocyte antigen (DLA) class II expression is controlled at the transcriptional level with proximal promoters. Differential expression of DLA class II molecules of antigen-presenting cells is reported to affect susceptibility to or protection from different immune-mediated diseases. The aim of this study was to evaluate, whether the variation in promoter areas of homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 Dobermans could explain why some dogs become afflicted with DH and others do not. Our findings suggest that promoter variants are not associated as risk modifiers in homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 Dobermans, but additional factors are needed. Nevertheless, our study indicates that the whole DLA block is associated to the disease.
Collapse
Affiliation(s)
- H Dyggve
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
| | | | | | | | | | | |
Collapse
|
157
|
Weissl J, Hülsmeyer V, Brauer C, Tipold A, Koskinen LL, Kyöstilä K, Lohi H, Sauter-Louis C, Wolf M, Fischer A. Disease progression and treatment response of idiopathic epilepsy in Australian Shepherd dogs. J Vet Intern Med 2011; 26:116-25. [PMID: 22182230 DOI: 10.1111/j.1939-1676.2011.00853.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 09/25/2011] [Accepted: 11/14/2011] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Idiopathic epilepsy (IE) in Australian Shepherds (ASs) occurs worldwide but there is a lack of description of the epilepsy syndrome in this breed. The ABCB1-1Δ mutation is more prevalent in ASs than in many other dog breeds. HYPOTHESIS Australian Shepherds suffer from a poorly controlled IE syndrome with prevailing severe courses. Seizure control and ABCB1-1Δ mutation might be related in this breed. ANIMALS Fifty ASs diagnosed with IE and 50 unaffected ASs. METHODS Predominant study design is a longitudinal cohort study. Pedigrees, medical records, seizure, and treatment data of ASs with IE were analyzed descriptively. Sex, color, and the ABCB1-1Δ genotype were compared between case and control groups and ASs with poorly or well-controlled seizures. Differences in survival times were assessed by logrank tests and Cox regression analysis. RESULTS Idiopathic epilepsy in ASs is dominated by moderate and severe clinical courses with the occurrence of cluster seizures and status epilepticus and a high seizure frequency. Poor seizure control and a high initial seizure frequency (≥10 seizure days/first 6 months) are associated with shorter survival times (P < .05). Poor seizure control, unrelated to the ABCB1(MDR1) genotype, is evident in 56% of epileptic ASs. Pedigree analysis suggests a genetic basis. CONCLUSION AND CLINICAL IMPORTANCE Frequent severe clinical courses, poor seizure control unrelated to the ABCB1(MDR1) genotype, and a young age at death compromise animal welfare and warrant further genetic studies to unravel the underlaying molecular mechanisms of IE and seizure control in the breed.
Collapse
Affiliation(s)
- J Weissl
- Clinic of Small Animal Medicine, Ludwig-Maximilians-University, Munich, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
158
|
Gould D, Pettitt L, McLaughlin B, Holmes N, Forman O, Thomas A, Ahonen S, Lohi H, O'Leary C, Sargan D, Mellersh C. ADAMTS17 mutation associated with primary lens luxation is widespread among breeds. Vet Ophthalmol 2011; 14:378-84. [PMID: 22050825 DOI: 10.1111/j.1463-5224.2011.00892.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Primary lens luxation (PLL) is a well-recognized, painful and potentially blinding inherited ocular condition in dogs. We screened PLL-affected dogs of 30 different breeds, to identify those which carried a previously described c.1473+1 G>A mutation in ADAMTS17 that is associated with PLL in Miniature Bull terriers, Lancashire Heelers, and Jack Russell terriers. This ADAMTS17 mutation was identified in PLL-affected dogs from 14 additional breeds. PLL-affected dogs from some breeds (most notably the Shar pei and the Brittany spaniel) did not carry the G1473+1A ADAMTS17 mutation, indicating they must suffer from a genetically distinct form of the condition. We also estimated the frequency of this ADAMTS17 mutation in some of the breeds. Our findings indicate the mutation segregates in a large number of different breeds of dog, many of which are terriers or breeds with terrier co-ancestry, but some of which have more diverse origins. Our results also indicate that the mutation is present at high frequency within most of the breeds in which it segregates. In the miniature bull terrier breed estimates of mutation frequency ranged from 0.27 to 0.39, corresponding to 7.3-15.2% PLL-affected dogs in this breed. We also identified an increased risk of PLL associated with heterozygosity at ADAMTS17, suggesting that carriers carry a low risk of developing PLL.
Collapse
Affiliation(s)
- David Gould
- Davies Veterinary Specialists, Manor Farm Business Park, Higham Gobion, Herts, UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
159
|
Seppälä EH, Jokinen TS, Fukata M, Fukata Y, Webster MT, Karlsson EK, Kilpinen SK, Steffen F, Dietschi E, Leeb T, Eklund R, Zhao X, Rilstone JJ, Lindblad-Toh K, Minassian BA, Lohi H. LGI2 truncation causes a remitting focal epilepsy in dogs. PLoS Genet 2011; 7:e1002194. [PMID: 21829378 PMCID: PMC3145619 DOI: 10.1371/journal.pgen.1002194] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [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: 12/07/2010] [Accepted: 06/05/2011] [Indexed: 12/17/2022] Open
Abstract
One quadrillion synapses are laid in the first two years of postnatal construction of the human brain, which are then pruned until age 10 to 500 trillion synapses composing the final network. Genetic epilepsies are the most common neurological diseases with onset during pruning, affecting 0.5% of 2–10-year-old children, and these epilepsies are often characterized by spontaneous remission. We previously described a remitting epilepsy in the Lagotto romagnolo canine breed. Here, we identify the gene defect and affected neurochemical pathway. We reconstructed a large Lagotto pedigree of around 34 affected animals. Using genome-wide association in 11 discordant sib-pairs from this pedigree, we mapped the disease locus to a 1.7 Mb region of homozygosity in chromosome 3 where we identified a protein-truncating mutation in the Lgi2 gene, a homologue of the human epilepsy gene LGI1. We show that LGI2, like LGI1, is neuronally secreted and acts on metalloproteinase-lacking members of the ADAM family of neuronal receptors, which function in synapse remodeling, and that LGI2 truncation, like LGI1 truncations, prevents secretion and ADAM interaction. The resulting epilepsy onsets at around seven weeks (equivalent to human two years), and remits by four months (human eight years), versus onset after age eight in the majority of human patients with LGI1 mutations. Finally, we show that Lgi2 is expressed highly in the immediate post-natal period until halfway through pruning, unlike Lgi1, which is expressed in the latter part of pruning and beyond. LGI2 acts at least in part through the same ADAM receptors as LGI1, but earlier, ensuring electrical stability (absence of epilepsy) during pruning years, preceding this same function performed by LGI1 in later years. LGI2 should be considered a candidate gene for common remitting childhood epilepsies, and LGI2-to-LGI1 transition for mechanisms of childhood epilepsy remission. Major remodeling of the neuronal synaptic network occurs during childhood. The quadrillion synapses formed till the end of age two are trimmed to 500 trillion by age 10 through a selective process of strengthening of ideal connections, removal of redundant ones, and formation of new contacts. Very little is known about the basic mechanisms that direct this massive reorganization that leads to the adult brain. The most common epilepsies of humans occur in childhood and are characterized by remission prior to adulthood. Not much is known about their genetics and basic remission mechanisms. We describe here a canine equivalent disease and identify the defective gene, Lgi2. We show that the gene product is a secreted protein and interacts with neuronal ADAM receptors known to be involved in the regulation of synaptic remodeling in the developing brain. Our work sheds important light on the basic mechanisms of the most common neurological disease of children and discloses processes of epilepsy remission. The identification of the first focal epilepsy gene in dogs has also enabled the development of a genetic test to identify carriers for breeding purposes.
Collapse
Affiliation(s)
- Eija H. Seppälä
- Department of Veterinary Biosciences, Department of Medical Genetics, Research Programs Unit, Molecular Medicine, University of Helsinki, Helsinki, Finland
- Department of Molecular Genetics, Folkhälsan Research Center, Helsinki, Finland
| | - Tarja S. Jokinen
- Department of Clinical Veterinary Sciences, University of Helsinki, Helsinki, Finland
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Cell Physiology, National Institute for Physiological Sciences and National Institutes of Natural Sciences, Okazaki, Japan
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Cell Physiology, National Institute for Physiological Sciences and National Institutes of Natural Sciences, Okazaki, Japan
- PRESTO, Japan Science and Technology Agency, Tokyo, Japan
| | - Matthew T. Webster
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Elinor K. Karlsson
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, United States of America
- FAS Center for Systems Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Sami K. Kilpinen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Frank Steffen
- Department for Small Animals, Neurology Services, University of Zurich, Zurich, Switzerland
| | - Elisabeth Dietschi
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Department of Clinical Veterinary Medicine, Division of Small Animal Orthopedics and Surgery, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Tosso Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Ranja Eklund
- Department of Veterinary Biosciences, Department of Medical Genetics, Research Programs Unit, Molecular Medicine, University of Helsinki, Helsinki, Finland
- Department of Molecular Genetics, Folkhälsan Research Center, Helsinki, Finland
| | - Xiaochu Zhao
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | - Jennifer J. Rilstone
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | - Kerstin Lindblad-Toh
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, United States of America
| | - Berge A. Minassian
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada
| | - Hannes Lohi
- Department of Veterinary Biosciences, Department of Medical Genetics, Research Programs Unit, Molecular Medicine, University of Helsinki, Helsinki, Finland
- Department of Molecular Genetics, Folkhälsan Research Center, Helsinki, Finland
- * E-mail:
| |
Collapse
|
160
|
Lequarré AS, Andersson L, André C, Fredholm M, Hitte C, Leeb T, Lohi H, Lindblad-Toh K, Georges M. LUPA: a European initiative taking advantage of the canine genome architecture for unravelling complex disorders in both human and dogs. Vet J 2011; 189:155-9. [PMID: 21752675 DOI: 10.1016/j.tvjl.2011.06.013] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The domestic dog offers a unique opportunity to explore the genetic basis of disease, morphology and behaviour. Humans share many diseases with our canine companions, making dogs an ideal model organism for comparative disease genetics. Using newly developed resources, genome-wide association studies in dog breeds are proving to be exceptionally powerful. Towards this aim, veterinarians and geneticists from 12 European countries are collaborating to collect and analyse the DNA from large cohorts of dogs suffering from a range of carefully defined diseases of relevance to human health. This project, named LUPA, has already delivered considerable results. The consortium has collaborated to develop a new high density single nucleotide polymorphism (SNP) array. Mutations for four monogenic diseases have been identified and the information has been utilised to find mutations in human patients. Several complex diseases have been mapped and fine mapping is underway. These findings should ultimately lead to a better understanding of the molecular mechanisms underlying complex diseases in both humans and their best friend.
Collapse
Affiliation(s)
- Anne-Sophie Lequarré
- Unit of Animal Genomics, GIGA-R and Faculty of Veterinary Medicine, University of Liège, Avenue de l'Hôpital 1, 4000 Liège, Belgium.
| | | | | | | | | | | | | | | | | |
Collapse
|
161
|
Short AD, Dunne A, Lohi H, Boulton S, Carter SD, Timofte D, Ollier WER. Characteristics of epileptic episodes in UK dog breeds: an epidemiological approach. Vet Rec 2011; 169:48. [DOI: 10.1136/vr.d1901] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- A. D. Short
- Centre for Integrated Genomic Medical Research; School of Cancer and Enabling Sciences; University of Manchester; Stopford Building Manchester M13 9PT
| | - A. Dunne
- Centre for Integrated Genomic Medical Research; School of Cancer and Enabling Sciences; University of Manchester; Stopford Building Manchester M13 9PT
| | - H. Lohi
- Department of Veterinary Biosciences, Program in Molecular Medicine; Folkhälsan Institute of Genetics; University of Helsinki; PO Box 63 00014 Helsinki Finland
| | - S. Boulton
- Vétoquinol UK, Vétoquinol House, Great Slade; Buckingham Industrial Park Buckingham MK18 1PA
| | - S. D. Carter
- School of Veterinary Science; University of Liverpool; Liverpool L69 7ZJ
| | - D. Timofte
- School of Veterinary Science; University of Liverpool; Liverpool L69 7ZJ
| | - W. E. R. Ollier
- Centre for Integrated Genomic Medical Research; School of Cancer and Enabling Sciences; University of Manchester; Stopford Building Manchester M13 9PT
| |
Collapse
|
162
|
Klütsch CFC, Seppälä EH, Fall T, Uhlén M, Hedhammar A, Lohi H, Savolainen P. Regional occurrence, high frequency but low diversity of mitochondrial DNA haplogroup d1 suggests a recent dog-wolf hybridization in Scandinavia. Anim Genet 2011; 42:100-3. [PMID: 20497152 PMCID: PMC3040290 DOI: 10.1111/j.1365-2052.2010.02069.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [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] [Indexed: 11/29/2022]
Abstract
The domestic dog mitochondrial DNA (mtDNA)-gene pool consists of a homogenous mix of haplogroups shared among all populations worldwide, indicating that the dog originated at a single time and place. However, one small haplogroup, subclade d1, found among North Scandinavian/Finnish spitz breeds at frequencies above 30%, has a clearly separate origin. We studied the genetic and geographical diversity for this phylogenetic group to investigate where and when it originated and whether through independent domestication of wolf or dog-wolf crossbreeding. We analysed 582 bp of the mtDNA control region for 514 dogs of breeds earlier shown to harbour d1 and possibly related northern spitz breeds. Subclade d1 occurred almost exclusively among Swedish/Finnish Sami reindeer-herding spitzes and some Swedish/Norwegian hunting spitzes, at a frequency of mostly 60–100%. Genetic diversity was low, with only four haplotypes: a central, most frequent, one surrounded by two haplotypes differing by an indel and one differing by a substitution. The substitution was found in a single lineage, as a heteroplasmic mix with the central haplotype. The data indicate that subclade d1 originated in northern Scandinavia, at most 480–3000 years ago and through dog-wolf crossbreeding rather than a separate domestication event. The high frequency of d1 suggests that the dog-wolf hybrid phenotype had a selective advantage.
Collapse
Affiliation(s)
- C F C Klütsch
- KTH-Royal Institute of Technology, Gene Technology, Roslagstullsbacken 21, 10691 Stockholm, Sweden
| | | | | | | | | | | | | |
Collapse
|
163
|
Farias FHG, Zeng R, Johnson GS, Wininger FA, Taylor JF, Schnabel RD, McKay SD, Sanders DN, Lohi H, Seppälä EH, Wade CM, Lindblad-Toh K, O'Brien DP, Katz ML. A truncating mutation in ATP13A2 is responsible for adult-onset neuronal ceroid lipofuscinosis in Tibetan terriers. Neurobiol Dis 2011; 42:468-74. [PMID: 21362476 DOI: 10.1016/j.nbd.2011.02.009] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 02/05/2011] [Accepted: 02/22/2011] [Indexed: 11/24/2022] Open
Abstract
A recessive, adult-onset neuronal ceroid-lipofuscinosis (NCL) occurs in Tibetan terriers. A genome-wide association study restricted this NCL locus to a 1.3Mb region of canine chromosome 2 which contains canine ATP13A2. NCL-affected dogs were homozygous for a single-base deletion in ATP13A2, predicted to produce a frameshift and premature termination codon. Homozygous truncating mutations in human ATP13A2 have been shown by others to cause Kufor-Rakeb syndrome (KRS), a rare neurodegenerative disease. These findings suggest that KRS is also an NCL, although analysis of KRS brain tissue will be needed to confirm this prediction. Generalized brain atrophy, behavioral changes, and cognitive decline occur in both people and dogs with ATP13A2 mutations; however, other clinical features differ between the species. For example, Tibetan terriers with NCL develop cerebellar ataxia not reported in KRS patients and KRS patients exhibit parkinsonism and pyramidal dysfunction not observed in affected Tibetan terriers. To see if ATP13A2 mutations could be responsible for some cases of human adult-onset NCL (Kufs disease), we resequenced ATP13A2 from 28 Kufs disease patients. None of these patients had ATP13A2 sequence variants likely to be causal for their disease, suggesting that mutations in this gene are not common causes of Kufs disease.
Collapse
Affiliation(s)
- Fabiana H G Farias
- Department of Veterinary Pathobiology, University of Missouri, Columbia, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
164
|
Tiira K, Escriou C, Thomas A, Renier S, de Citres CD, Koskinen L, Kareinen L, Arnold P, Lohi H. Phenotypic and genetic characterization of tail chasing in bull terriers. J Vet Behav 2011. [DOI: 10.1016/j.jveb.2010.09.005] [Citation(s) in RCA: 4] [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: 11/17/2022]
|
165
|
Zangerl B, Wickström K, Slavik J, Lindauer SJ, Ahonen S, Schelling C, Lohi H, Guziewicz KE, Aguirre GD. Assessment of canine BEST1 variations identifies new mutations and establishes an independent bestrophinopathy model (cmr3). Mol Vis 2010; 16:2791-804. [PMID: 21197113 PMCID: PMC3008713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 12/11/2010] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Mutations in bestrophin 1 (BEST1) are associated with a group of retinal disorders known as bestrophinopathies in man and canine multifocal retinopathies (cmr) in the dog. To date, the dog is the only large animal model suitable for the complex characterization and in-depth studies of Best-related disorders. In the first report of cmr, the disease was described in a group of mastiff-related breeds (cmr1) and the Coton de Tulear (cmr2). Additional breeds, e.g., the Lapponian herder (LH) and others, subsequently were recognized with similar phenotypes, but linked loci are unknown. Analysis of the BEST1 gene aimed to identify mutations in these additional populations and extend our understanding of genotype-phenotype associations. METHODS Animals were subjected to routine eye exams, phenotypically characterized, and samples were collected for molecular studies. Known BEST1 mutations were assessed, and the canine BEST1 coding exons were amplified and sequenced in selected individuals that exhibited a cmr compatible phenotype but that did not carry known mutations. Resulting sequence changes were genotyped in several different breeds and evaluated in the context of the phenotype. RESULTS Seven novel coding variants were identified in exon 10 of cBEST1. Two linked mutations were associated with cmr exclusive to the LH breed (cmr3). Two individuals of Jämthund and Norfolk terrier breeds were heterozygous for two conservative changes, but these were unlikely to have disease-causing potential. Another three substitutions were found in the Bernese mountain dog that were predicted to have a deleterious effect on protein function. Previously reported mutations were excluded from segregation in these populations, but cmr1 was confirmed in another mastiff-related breed, the Italian cane corso. CONCLUSIONS A third independent canine model for human bestrophinopathies has been established in the LH breed. While exhibiting a phenotype comparable to cmr1 and cmr2, the novel cmr3 mutation is predicted to be based on a distinctly different molecular mechanism. So far cmr2 and cmr3 are exclusive to a single dog breed each. In contrast, cmr1 is found in multiple related breeds. Additional sequence alterations identified in exon 10 of cBEST1 in other breeds exhibit potential disease-causing features. The inherent genetic and phenotypic variation observed with retinal disorders in canines is complicated further by cmr3 being one of four distinct genetic retinal traits found to segregate in LH. Thus, a combination of phenotypic, molecular, and population analysis is required to establish a strong phenotype-genotype association. These results indicate that cmr has a larger impact on the general dog population than was initially suspected. The complexity of these models further confirms the similarity to human bestrophinopathies. Moreover, analyses of multiple canine models will provide additional insight into the molecular basis underlying diseases caused by mutations in BEST1.
Collapse
Affiliation(s)
- Barbara Zangerl
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | | | - Julianna Slavik
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Sarah J. Lindauer
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Saija Ahonen
- Department of Veterinary Biosciences, Department of Medical Genetics, Program in Molecular Medicine, University of Helsinki and Folkhälsan Research Institute, Helsinki, Finland
| | - Claude Schelling
- Department of Animal Sciences, Swiss Federal Institute of Technology Zurich and Vetsuisse Faculty Zurich, University of Zurich, Zurich, Switzerland
| | - Hannes Lohi
- Department of Veterinary Biosciences, Department of Medical Genetics, Program in Molecular Medicine, University of Helsinki and Folkhälsan Research Institute, Helsinki, Finland
| | - Karina E. Guziewicz
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Gustavo D. Aguirre
- Section of Ophthalmology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
166
|
Flisikowski K, Venhoranta H, Nowacka-Woszuk J, McKay SD, Flyckt A, Taponen J, Schnabel R, Schwarzenbacher H, Szczerbal I, Lohi H, Fries R, Taylor JF, Switonski M, Andersson M. A novel mutation in the maternally imprinted PEG3 domain results in a loss of MIMT1 expression and causes abortions and stillbirths in cattle (Bos taurus). PLoS One 2010; 5:e15116. [PMID: 21152099 PMCID: PMC2994898 DOI: 10.1371/journal.pone.0015116] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [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: 09/08/2010] [Accepted: 10/21/2010] [Indexed: 12/27/2022] Open
Abstract
Congenital malformations resulting in late abortions and stillbirths affect the economic wellbeing of producers and the welfare of cattle in breeding programs. An extremely high incidence of stillbirths of “half-sized” calves of normal karyotype and uninflated lungs was diagnosed in the progeny of the Finnish Ayrshire (Bos taurus) bull - YN51. No other visible anatomical abnormalities were apparent in the stillborn calves. We herein describe the positional identification of a 110 kb microdeletion in the maternally imprinted PEG3 domain that results in a loss of paternal MIMT1 expression and causes late term abortion and stillbirth in cattle. Using the BovineSNP50 BeadChip we performed a genome-wide half-sib linkage analysis that identified a 13.3 Mb associated region on BTA18 containing the maternally imprinted PEG3 domain. Within this cluster we found a 110 kb microdeletion that removes a part of the non-protein coding MER1 repeat containing imprinted transcript 1 gene (MIMT1). To confirm the elimination of gene expression in calves inheriting this deletion, we examined the mRNA levels of the three maternally imprinted genes within the PEG3 domain, in brain and cotyledon tissue collected from eight fetuses sired by the proband. None of the fetuses that inherited the microdeletion expressed MIMT1 in either tissue. The mutation, when inherited from the sire, is semi-lethal for his progeny with an observed mortality rate of 85%. The survival of 15% is presumably due to the incomplete silencing of maternally inherited MIMT1 alleles. We designed a PCR-based assay to confirm the existence of the microdeletion in the MIMT1 region that can be used to assist cattle breeders in preventing the stillbirths.
Collapse
|
167
|
Jokinen P, Rusanen EM, Kennedy LJ, Lohi H. MHC class II risk haplotype associated with canine chronic superficial keratitis in German Shepherd dogs. Vet Immunol Immunopathol 2010; 140:37-41. [PMID: 21144596 DOI: 10.1016/j.vetimm.2010.11.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 11/03/2010] [Accepted: 11/11/2010] [Indexed: 01/25/2023]
Abstract
Canine chronic superficial keratitis (CSK) is an inflammatory ocular disease of an autoimmune origin leading to blindness if untreated. The main symptoms of CSK are progressive, bilateral vascularisation, fibrous tissue formation and pigmentation of the anterior corneal stroma. Although CSK is found in many breeds it is most prevalent in German Shepherd dogs (GSDs). Since Major Histocompatibility Complex (MHC) class II is associated with several autoimmune diseases in dogs we investigated the possible role of DLA-DRB1, -DQA1 and -DQB1 in GSDs affected with CSK. Our study population included 25 healthy controls and 30 CSK dogs. Most of the affected dogs were females suggesting a female predisposition. We identified 11 unevenly distributed haplotypes of which DLA-DRB1*01501/DQA1*00601/DQB1*00301 was significantly associated with the CSK dogs (OR=2.67, CI=1.17-6.44, p=0.02). We also found that overall homozygosity of MHC class II increases risk for CSK (OR=4.37, CI=1.27-18.46, p=0.02) and homozygosity of the risk haplotype by over eight-fold (OR=8.5, 95% CI=1.4-224, p=0.017). This study identifies a MHC class II risk haplotype for CSK in GSD and further supports the autoimmune origin of the disease.
Collapse
Affiliation(s)
- Päivi Jokinen
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Agnes Sjöbergin katu 2, P.O. Box 66, 00014 University of Helsinki, Finland.
| | | | | | | |
Collapse
|
168
|
Ke X, Kennedy LJ, Short AD, Seppälä EH, Barnes A, Clements DN, Wood SH, Carter SD, Happ GM, Lohi H, Ollier WER. Assessment of the functionality of genome-wide canine SNP arrays and implications for canine disease association studies. Anim Genet 2010; 42:181-90. [DOI: 10.1111/j.1365-2052.2010.02132.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
169
|
Klütsch CFC, Seppälä EH, Uhlén M, Lohi H, Savolainen P. Segregation of point mutation heteroplasmy in the control region of dog mtDNA studied systematically in deep generation pedigrees. Int J Legal Med 2010; 125:527-35. [PMID: 21049272 PMCID: PMC3115052 DOI: 10.1007/s00414-010-0524-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [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: 08/12/2010] [Accepted: 10/18/2010] [Indexed: 12/04/2022]
Abstract
Heteroplasmy, the presence of two or more variants in an organism, may render mitochondrial DNA (mtDNA)-based individual identification challenging in forensic analysis. However, the variation of heteroplasmic proportions and the segregation of heteroplasmic variants through generations and within families have not been systematically described at a large scale in animals such as the domestic dog. Therefore, we performed the largest study to date in domestic dogs and screened a 582-bp-long fragment of the mtDNA control region in 180 individuals in 58 pedigrees for signs of heteroplasmy. We identified three pedigrees (5.17%) with heteroplasmic point mutations. To follow the segregation of the point mutations, we then analyzed 131 samples from these three independent pedigrees and found significant differences in heteroplasmy between generations and among siblings. Frequently (10% of cases), the proportion of one base changed from 0–10% to 80–90% (as judged from Sanger electropherograms) between generations and varied to a similar extent among siblings. We included also a literature review of heteroplasmic and potential mutational hot spot positions in the studied region which showed that all heteroplasmic positions appear to be mutational hot spots. Thus, although heteroplasmy may be used to increase the significance of a match in forensic case work, it may also cause erroneous exclusion of related individuals because of sharp switches from one state to the other within a single generation or among siblings especially in the presented mutational hot spots.
Collapse
Affiliation(s)
- Cornelya F C Klütsch
- KTH-Royal Institute of Technology, Gene Technology, Roslagstullsbacken 21, 10691 Stockholm, Sweden
| | | | | | | | | |
Collapse
|
170
|
Dyggve H, Kennedy LJ, Meri S, Spillmann T, Lohi H, Speeti M. Association of Doberman hepatitis to canine major histocompatibility complex II. ACTA ACUST UNITED AC 2010; 77:30-5. [PMID: 20946186 DOI: 10.1111/j.1399-0039.2010.01575.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Doberman hepatitis (DH) is a chronic and progressive inflammatory liver disease that mainly affects female dogs. The high incidence of chronic hepatitis in Dobermans is suggestive of a genetic predisposition. DH is characterized by mononuclear cell infiltration and copper accumulation in the liver and major histocompatibility complex (MHC) class II antigen expression in the hepatocytes. In dogs, the MHC is referred to as the dog leukocyte antigen (DLA) system. In this study, the potential role of DLA genes in DH was investigated by sequence-based typing in the exon 2 of DLA-DRB1, -DQA1 and -DQB1. The case group comprised 37 Dobermans with subclinical or clinical DH. The control group consisted of 37 healthy Dobermans, with normal liver enzyme values and without immunosuppressive medication. The control dogs were over 10 years old to include dogs with the lowest genetic risk of DH. Our results indicate that Dobermans with homozygous DLA-DRB1*00601/DQA1*00401/DQB1*01303 [odds ratio (OR) = 14.9, confidence limit (CL) = 3.1-71.7, P < 0.00005], especially with homozygosity for DLA-DRB1*00601 (P < 0.0005), are susceptible to DH. The DQ heterodimer DLA-DQA1*00901/DQB1*00101 and the allele DLA-DRB1*01501 appear to confer protection against DH (P < 0.001). Allele and haplotype frequencies were compared using chi-squared statistics. The disease shows a complex pattern of inheritance, but the observed DLA class II association with DH suggests a role for the immune system in the development of the disease.
Collapse
Affiliation(s)
- H Dyggve
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
| | | | | | | | | | | |
Collapse
|
171
|
Short AD, Mellersh CS, Platt H, Carter SD, Timofte D, Lohi H, Ollier WER. Exonic mutations in the L2HGDH
gene in Staffordshire bull terriers. Vet Rec 2010; 167:455-7. [DOI: 10.1136/vr.c4476] [Citation(s) in RCA: 8] [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: 11/03/2022]
Affiliation(s)
- A. D. Short
- Centre for Integrated Genomic Medical Research; School of Cancer and Enabling Sciences; University of Manchester; Stopford Building Manchester M13 9PT
| | - C. S. Mellersh
- Animal Health Trust; Lanwades Park, Kentford Newmarket Suffolk CB8 7UU
| | - H. Platt
- Centre for Integrated Genomic Medical Research; School of Cancer and Enabling Sciences; University of Manchester; Stopford Building Manchester M13 9PT
| | - S. D. Carter
- School of Veterinary Science; University of Liverpool; Liverpool L69 7ZL
| | - D. Timofte
- School of Veterinary Science; University of Liverpool; Liverpool L69 7ZL
| | - H. Lohi
- Department of Basic Veterinary Sciences and Medical Genetics, Programme in Molecular Medicine; University of Helsinki; Folkhälsan Institute of Genetics; PO Box 63, 00014 University of Helsinki Finland
| | - W. E. R. Ollier
- Centre for Integrated Genomic Medical Research; School of Cancer and Enabling Sciences; University of Manchester; Stopford Building Manchester M13 9PT
| |
Collapse
|
172
|
Farias FHG, Johnson GS, Taylor JF, Giuliano E, Katz ML, Sanders DN, Schnabel RD, McKay SD, Khan S, Gharahkhani P, O'Leary CA, Pettitt L, Forman OP, Boursnell M, McLaughlin B, Ahonen S, Lohi H, Hernandez-Merino E, Gould DJ, Sargan DR, Mellersh C. An ADAMTS17 splice donor site mutation in dogs with primary lens luxation. Invest Ophthalmol Vis Sci 2010; 51:4716-21. [PMID: 20375329 DOI: 10.1167/iovs.09-5142] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To identify the genetic cause of isolated canine ectopia lentis, a well-characterized veterinary disease commonly referred to as primary lens luxation (PLL) and to compare the canine disease with a newly described human Weill-Marchesani syndrome (WMS)-like disease of similar genetic etiology. METHODS Genomewide association analysis and fine mapping by homozygosity were used to identify the chromosomal segment harboring the PLL locus. The resequencing of a regional candidate gene was used to discover a mutation in a splice donor site predicted to cause exon skipping. Exon skipping was confirmed by reverse transcription-polymerase chain reaction amplification of RNA isolated from PLL-affected eyes and from skin fibroblast cultures from PLL-affected dogs. An allelic discrimination assay was used to genotype individual dogs at the splice donor site mutation. RESULTS The PLL locus was mapped to a 664-kb region of canine chromosome 3 containing regional candidate gene ADAMTS17. Resequencing ADAMTS17 revealed a GT-->AT splice-donor-site mutation at the 5' end of intron 10. The predicted exon 10 skipping and resultant frame shift were confirmed with RNA derived from PLL-affected dogs. The ADAMTS17 mutation was significantly associated with clinical PLL in three different dog breeds. CONCLUSIONS A truncating mutation in canine ADAMTS17 causes PLL, a well-characterized veterinary disease, which can now be compared to a recently described rare WMS-like disease caused by truncating mutations of the human ADAMTS17 ortholog.
Collapse
Affiliation(s)
- Fabiana H G Farias
- Department of Veterinary Pathobiology, Mason Eye Institute, Universoty of Missouri, Columbia, MO 65211, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
173
|
Mellersh CS, McLaughlin B, Ahonen S, Pettitt L, Lohi H, Barnett KC. Mutation in HSF4 is associated with hereditary cataract in the Australian Shepherd. Vet Ophthalmol 2010; 12:372-8. [PMID: 19883468 DOI: 10.1111/j.1463-5224.2009.00735.x] [Citation(s) in RCA: 20] [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] [Indexed: 11/28/2022]
Abstract
Cataracts are a leading cause of blindness in dogs with approximately 100 breeds affected by primary hereditary forms. Despite the large number of breeds affected with hereditary cataracts (HC) little is known about the genetics of the condition, and to date only a single gene, HSF4, has been implicated in the development of the disease in dogs. We previously identified a recessively inherited 1-bp insertion in the transcription factor gene HSF4 resulting in the loss of the open reading frame in Boston terriers and Staffordshire bull terriers. While testing the insertion mutation in other breeds with HC, we identified a 1-bp deletion at the same nucleotide of HSF4 in some Australian Shepherds with cataract. Using DNA samples from almost 400 privately owned Australian Shepherds we have investigated the association between the deletion mutation in HSF4 and cataracts in this breed. We conclude that the mutation is significantly associated with cataracts and that a dog carrying the mutation is approximately 17 times more likely to develop binocular cataracts than dogs that are clear of the mutation. The data also indicate that additional mutations associated with the development of cataracts are likely to be co-segregating in the Australian Shepherd population.
Collapse
Affiliation(s)
- Cathryn S Mellersh
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK.
| | | | | | | | | | | |
Collapse
|
174
|
Hughes AM, Jokinen P, Bannasch DL, Lohi H, Oberbauer AM. Association of a dog leukocyte antigen class II haplotype with hypoadrenocorticism in Nova Scotia Duck Tolling Retrievers. ACTA ACUST UNITED AC 2010; 75:684-90. [DOI: 10.1111/j.1399-0039.2010.01440.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
175
|
Wilbe M, Jokinen P, Hermanrud C, Kennedy LJ, Strandberg E, Hansson-Hamlin H, Lohi H, Andersson G. MHC class II polymorphism is associated with a canine SLE-related disease complex. Immunogenetics 2009; 61:557-64. [PMID: 19636550 DOI: 10.1007/s00251-009-0387-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Accepted: 07/01/2009] [Indexed: 11/26/2022]
Abstract
Nova Scotia duck tolling retrievers are predisposed to a SLE-related disease complex including immune-mediated rheumatic disease (IMRD) and steroid-responsive meningitis-arteritis (SRMA). IMRD involves symptoms that resemble those seen in systemic autoimmune rheumatic diseases, such as systemic lupus erythematosus, SLE, or SLE-related diseases, in humans. This disease complex involves persistent lameness, stiffness, mainly after resting, and palpable pain from several joints of extremities. The majority of affected dogs display antinuclear autoantibody (ANA)-reactivity. SRMA is manifested in young dogs with high fever and neck stiffness and can be treated with corticosteroids. We have investigated the possible role of MHC class II as a genetic risk factor in IMRD and SRMA etiology. We performed sequence-based typing of the DLA-DRB1, -DQA1, and -DQB1 class II loci in a total of 176 dogs including 51 IMRD (33 ANA-positive), 49 SRMA cases, and 78 healthy controls (two dogs were both IMRD- and SRMA-affected). Homozygosity for the risk haplotype DRB1*00601/DQA1*005011/DQB1*02001 increased the risk for IMRD (OR = 4.9; ANA-positive IMRD: OR = 7.2) compared with all other genotypes. There was a general heterozygote advantage, homozygotes had OR = 4.4 (ANA-positive IMRD: OR = 8.9) compared with all heterozygotes. The risk haplotype contains the five amino acid epitope RARAA, known as the shared epitope for rheumatoid arthritis. No association was observed for SRMA. We conclude that DLA class II is a highly significant genetic risk factor for ANA-positive IMRD. The results indicate narrow diversity of DLA II haplotypes and identify an IMRD-related risk haplotype, which becomes highly significant in homozygous dogs.
Collapse
Affiliation(s)
- Maria Wilbe
- Department of Animal Breeding and Genetics, BMC, Swedish University of Agricultural Sciences, Box 597, SE-751 24, Uppsala, Sweden.
| | | | | | | | | | | | | | | |
Collapse
|
176
|
Hytönen MK, Grall A, Hédan B, Dréano S, Seguin SJ, Delattre D, Thomas A, Galibert F, Paulin L, Lohi H, Sainio K, André C. Ancestral T-box mutation is present in many, but not all, short-tailed dog breeds. J Hered 2008; 100:236-40. [PMID: 18854372 DOI: 10.1093/jhered/esn085] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Dogs differ greatly in their morphological characteristics including various tail phenotypes. Congenitally short-tailed dogs are present in many breeds; however, the causative mutation located in the T-box transcription factor T gene (C189G) had only been described in the bobtailed Pembroke Welsh Corgis. We investigated here the presence of the T gene mutation in 23 other breeds (360 dogs, including 156 natural short tailed) in which natural bobtailed dogs exist. In the 17 breeds in which the C189G mutation was observed, there was a perfect correlation between this mutation and the short-tail phenotype. However, 6 breeds did not carry the known substitution or any other mutations in the T gene coding regions. No dogs were found to be homozygous for the C189G mutation, suggesting that the homozygous condition is lethal. In order to study the effect of the T gene mutation on litter size, we compared the number of puppies born from short-tailed parents to that born from long-tailed parents. In the Swedish Vallhund breed, we observed a 29% decrease in the litter size when both parents were short tailed. Given that the T gene mutation is not present in all breeds of short-tailed dog, there must be yet other genetic factors affecting tail phenotypes to be discovered.
Collapse
Affiliation(s)
- Marjo K Hytönen
- Medical Biochemistry and Developmental Biology, Institute of Biomedicine, University of Helsinki, PO Box 63, 00014 Helsinki, Finland.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
177
|
Drögemüller C, Karlsson EK, Hytönen MK, Perloski M, Dolf G, Sainio K, Lohi H, Lindblad-Toh K, Leeb T. A mutation in hairless dogs implicates FOXI3 in ectodermal development. Science 2008; 321:1462. [PMID: 18787161 DOI: 10.1126/science.1162525] [Citation(s) in RCA: 121] [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] [Indexed: 11/02/2022]
Abstract
Mexican and Peruvian hairless dogs and Chinese crested dogs are characterized by missing hair and teeth, a phenotype termed canine ectodermal dysplasia (CED). CED is inherited as a monogenic autosomal semidominant trait. With genomewide association analysis we mapped the CED mutation to a 102-kilo-base pair interval on chromosome 17. The associated interval contains a previously uncharacterized member of the forkhead box transcription factor family (FOXI3), which is specifically expressed in developing hair and teeth. Mutation analysis revealed a frameshift mutation within the FOXI3 coding sequence in hairless dogs. Thus, we have identified FOXI3 as a regulator of ectodermal development.
Collapse
|
178
|
Kennedy LJ, O'Neill T, House A, Barnes A, Kyöstilä K, Innes J, Fretwell N, Day MJ, Catchpole B, Lohi H, Ollier WER. Risk of anal furunculosis in German shepherd dogs is associated with the major histocompatibility complex. ACTA ACUST UNITED AC 2007; 71:51-6. [PMID: 17999655 DOI: 10.1111/j.1399-0039.2007.00964.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Anal furunculosis (AF) is a chronic, progressive inflammatory disease of the perianal tissues most frequently affecting middle-aged or older German Shepherd dogs (GSD). Because this breed accounts for over 80% of all reported cases, there is likely to be a genetic association with disease susceptibility. Although there are some similarities with perianal fistulation that occurs in human Crohn's disease, the aetiology and pathogenesis of AF are still poorly understood. Recent research has suggested an immune-mediated aetiology, and evidence for this has been further provided by clinical responses to the immunosuppressive drug cyclosporin. The aim of the current study was to investigate canine major histocompatibility complex immune response genes. Dog leucocyte antigen class II alleles and haplotypes were characterised by sequence-based typing of 107 GSD affected with AF and 196 breed-matched controls collected in the UK. A highly significant association of DLA-DRB1*00101 with the presence of AF was observed (OR = 5.01, CI = 2.7-9.3, P < 0.00000001). This association was confirmed in a second cohort of GSD collected in Finland. Homozygosity for this allele is associated with an earlier disease onset.
Collapse
Affiliation(s)
- L J Kennedy
- Centre for Integrated Genomic Medical Research, University of Manchester, Manchester, UK.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
179
|
Jokinen TS, Metsähonkala L, Bergamasco L, Viitmaa R, Syrjä P, Lohi H, Snellman M, Jeserevics J, Cizinauskas S. Benign familial juvenile epilepsy in Lagotto Romagnolo dogs. J Vet Intern Med 2007; 21:464-71. [PMID: 17552452 DOI: 10.1892/0891-6640(2007)21[464:bfjeil]2.0.co;2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Idiopathic childhood epilepsies with benign outcomes are well recognized in human medicine, but are not reported in veterinary literature. We recognized such a neurologic syndrome in Lagotto Romagnolo dogs. ANIMALS Twenty-five Lagotto Romagnolo puppies from 9 different litters examined because of simple or complex focal seizures and 3 adult Lagotto Romagnolo dogs exhibiting similar clinical signs were used. METHODS Clinical and diagnostic evaluations of affected dogs were conducted, including electromyography, electroencephalography, and other testing. RESULTS Seizures in puppies began at 5 to 9 weeks of age and usually resolved spontaneously by 8 to 13 weeks. Those with the most severe seizures also had signs of neurologic disease between these seizures, including generalized ataxia and hypermetria. There were no abnormalities in routine laboratory screenings of blood, urine, and cerebrospinal fluid. Electromyography, brainstem auditory-evoked potentials, and magnetic resonance imaging revealed no specific and consistent abnormalities. Fourteen of 16 (87.5%) affected puppies and 2 of 3 (67%) adult dogs revealed epileptiform activity in the electroencephalogram. Histopathologic examination in 1 puppy and 1 adult dog revealed lesions of Purkinje cell inclusions and vacuolation of their axons restricted to the cerebellum. Pedigree analysis suggests an autosomal recessive mode of inheritance. CONCLUSIONS AND CLINICAL IMPORTANCE This disorder, with simple or complex focal seizures and cerebellar lesions, represents a newly recognized epileptic syndrome in dogs.
Collapse
Affiliation(s)
- T S Jokinen
- Department of Clinical Veterinary Sciences, University of Helsinki, Finland.
| | | | | | | | | | | | | | | | | |
Collapse
|
180
|
Siintola E, Topcu M, Aula N, Lohi H, Minassian BA, Paterson AD, Liu XQ, Wilson C, Lahtinen U, Anttonen AK, Lehesjoki AE. The novel neuronal ceroid lipofuscinosis gene MFSD8 encodes a putative lysosomal transporter. Am J Hum Genet 2007; 81:136-46. [PMID: 17564970 PMCID: PMC1950917 DOI: 10.1086/518902] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Accepted: 04/13/2007] [Indexed: 11/03/2022] Open
Abstract
The late-infantile-onset forms are the most genetically heterogeneous group among the autosomal recessively inherited neurodegenerative disorders, the neuronal ceroid lipofuscinoses (NCLs). The Turkish variant was initially considered to be a distinct genetic entity, with clinical presentation similar to that of other forms of late-infantile-onset NCL (LINCL), including age at onset from 2 to 7 years, epileptic seizures, psychomotor deterioration, myoclonus, loss of vision, and premature death. However, Turkish variant LINCL was recently found to be genetically heterogeneous, because mutations in two genes, CLN6 and CLN8, were identified to underlie the disease phenotype in a subset of patients. After a genomewide scan with single-nucleotide-polymorphism markers and homozygosity mapping in nine Turkish families and one Indian family, not linked to any of the known NCL loci, we mapped a novel variant LINCL locus to chromosome 4q28.1-q28.2 in five families. We identified six different mutations in the MFSD8 gene (previously denoted "MGC33302"), which encodes a novel polytopic 518-amino acid membrane protein that belongs to the major facilitator superfamily of transporter proteins. MFSD8 is expressed ubiquitously, with several alternatively spliced variants. Like the majority of the previously identified NCL proteins, MFSD8 localizes mainly to the lysosomal compartment. However, the function of MFSD8 remains to be elucidated. Analysis of the genome-scan data suggests the existence of at least three more genes in the remaining five families, further corroborating the great genetic heterogeneity of LINCLs.
Collapse
Affiliation(s)
- Eija Siintola
- Folkhälsan Institute of Genetics, Biomedicum Helsinki, P.O. Box 63 (Haartmaninkatu 8), 00014 University of Helsinki, Helsinki, Finland
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
181
|
Jokinen T, Metsähonkala L, Bergamasco L, Viitmaa R, Syrjä P, Lohi H, Snellman M, Jeserevics J, Cizinauskas S. Benign Familial Juvenile Epilepsy in Lagotto Romagnolo Dogs. J Vet Intern Med 2007. [DOI: 10.1111/j.1939-1676.2007.tb02991.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
182
|
Lohi H, Turnbull J, Zhao XC, Pullenayegum S, Ianzano L, Yahyaoui M, Mikati MA, Quinn NP, Franceschetti S, Zara F, Minassian BA. Genetic diagnosis in Lafora disease. Neurology 2007; 68:996-1001. [PMID: 17389303 DOI: 10.1212/01.wnl.0000258561.02248.2f] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Lafora disease (LD) can be diagnosed by skin biopsy, but this approach has both false negatives and false positives. Biopsies of other organs can also be diagnostic but are more invasive. Genetic diagnosis is also possible but can be inconclusive, for example, in patients with only one heterozygous EPM2A mutation and patients with apparently homozygous EPM2B mutations where one parent is not a carrier of the mutation. We sought to identify occult mutations and clarify the genotypes and confirm the diagnosis of LD in patients with apparent nonrecessive disease inheritance. We used single nucleotide polymorphism, quantitative PCR, and fluorescent in situ hybridization analyses. We identified large EPM2A and EPM2B deletions undetectable by PCR in the heterozygous state and describe simple methods for their routine detection. We report a coding sequence change in several patients and describe why the pathogenic role of this change remains unclear. We confirm that adult-onset LD is due to EPM2B mutations. Finally, we report major intrafamilial heterogeneity in age at onset in LD.
Collapse
Affiliation(s)
- H Lohi
- Program in Genetics and Genomic Biology and Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
183
|
Korhonen MK, Raevaara TE, Lohi H, Nyström M. Conditional nuclear localization of hMLH3 suggests a minor activity in mismatch repair and supports its role as a low-risk gene in HNPCC. Oncol Rep 2007; 17:351-4. [PMID: 17203173] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
DNA mismatch repair (MMR) mechanism contributes to the maintenance of genomic stability. Loss of MMR function predisposes to a mutator cell phenotype, microsatellite instability (MSI) and cancer, especially hereditary non-polyposis colorectal cancer (HNPCC). To date, five MMR genes, hMSH2, hMSH6, hMLH1, hPMS2, and hMLH3 are associated with HNPCC. Although, hMLH3 is suggested to be causative in HNPCC, its relevance to MMR needs to be confirmed to reliably assess significance of the inherited sequence variations in it. Recently, a human heterodimer hMLH1/hMLH3 (hMutLgamma) was shown to be able to assist hMLH1/hPMS2 (hMutLalpha) in the repair of mismatches in vitro. To repair mismatches in vivo, hMLH3 ought to localize in the nucleus. Our immunofluorescence analyses indicated that when all the three MutL homologues are natively expressed in human cells, endogenous hMLH1 and hPMS2 localize in the nucleus, whereas hMLH3 stays in the cytoplasm. Absence of hPMS2 and co-expression of hMLH3 with hMLH1 results in its partial nuclear localization. Our results are clinically relevant since they show that in the nuclear localization hMLH3 is dependent on hMLH1 and competitive with hPMS2. The continuous nuclear localization of hMLH1 and hPMS2 suggests that in vivo, hPMS2 (hMutLalpha) has a major activity in MMR. In absence of hPMS2, hMLH3 (hMutLgamma) is located in the nucleus, suggesting a conditional activity in MMR and supporting its role as a low-risk gene in HNPCC.
Collapse
Affiliation(s)
- Mari K Korhonen
- Department of Biological and Environmental Sciences, Genetics, University of Helsinki, FI-00014 Helsinki, Finland
| | | | | | | |
Collapse
|
184
|
Korhonen M, Raevaara T, Lohi H, Nyström M. Conditional nuclear localization of hMLH3 suggests a minor activity in mismatch repair and supports its role as a low-risk gene in HNPCC. Oncol Rep 2007. [DOI: 10.3892/or.17.2.351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
185
|
Petel-Galil Y, Ben-Zeev B, Greenbaum I, Vecsler M, Goldman B, Lohi H, Minassian BA, Gak E. Comprehensive diagnosis of Rett's syndrome relying on genetic, epigenetic and expression evidence of deficiency of the methyl-CpG-binding protein 2 gene: study of a cohort of Israeli patients. J Med Genet 2007; 44:e56. [PMID: 17407838] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
BACKGROUND Despite advances in the characterisation of mutations in the MECP2-coding region, a small proportion of classic RTT cases remain without recognisable mutations. OBJECTIVE AND METHODS To identify previously unknown mutations, a quantitative assay was established, providing estimates of MECP2_e1 and MECP2_e2 expression levels in peripheral blood. A systematic analysis of an Israeli cohort of 82 patients with classic and atypical RTT is presented, including sequence analysis of the MECP2-coding region, MLPA, XCI and quantitative expression assays. RESULTS AND CONCLUSION A novel mis-sense mutation at ca 453C-->T (pD151E), resulting in a change of a conserved residue at the methyl-binding domain, and a rare GT deletion of intron 1 donor splice site are reported. It is shown that various MECP2 mutations had distinct effects on MECP2 expression levels in peripheral blood. The most significant (p<0.001) reduction in the expression of both MECP2 isoforms was related to the presence of the intron 1 donor splice-site mutation. Using quantitative expression assays, it was shown that several patients with classic and atypical RTT with no mutation findings had significantly lower MECP2 expression levels. Further research on these patients may disclose still elusive non-coding regulatory MECP2 mutations.
Collapse
Affiliation(s)
- Y Petel-Galil
- Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | | | | | | | | | | | | | | |
Collapse
|
186
|
Petel-Galil Y, Benteer B, Galil YP, Zeev BB, Greenbaum I, Vecsler M, Goldman B, Lohi H, Minassian BA, Gak E. Comprehensive diagnosis of Rett's syndrome relying on genetic, epigenetic and expression evidence of deficiency of the methyl-CpG-binding protein 2 gene: study of a cohort of Israeli patients. J Med Genet 2006; 43:e56. [PMID: 17142618 PMCID: PMC2563193 DOI: 10.1136/jmg.2006.041285] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Despite advances in the characterisation of mutations in the MECP2-coding region, a small proportion of classic RTT cases remain without recognisable mutations. OBJECTIVE AND METHODS To identify previously unknown mutations, a quantitative assay was established, providing estimates of MECP2_e1 and MECP2_e2 expression levels in peripheral blood. A systematic analysis of an Israeli cohort of 82 patients with classic and atypical RTT is presented, including sequence analysis of the MECP2-coding region, MLPA, XCI and quantitative expression assays. RESULTS AND CONCLUSION A novel mis-sense mutation at ca 453C-->T (pD151E), resulting in a change of a conserved residue at the methyl-binding domain, and a rare GT deletion of intron 1 donor splice site are reported. It is shown that various MECP2 mutations had distinct effects on MECP2 expression levels in peripheral blood. The most significant (p<0.001) reduction in the expression of both MECP2 isoforms was related to the presence of the intron 1 donor splice-site mutation. Using quantitative expression assays, it was shown that several patients with classic and atypical RTT with no mutation findings had significantly lower MECP2 expression levels. Further research on these patients may disclose still elusive non-coding regulatory MECP2 mutations.
Collapse
|
187
|
Wang W, Lohi H, Skurat AV, DePaoli-Roach AA, Minassian BA, Roach PJ. Glycogen metabolism in tissues from a mouse model of Lafora disease. Arch Biochem Biophys 2006; 457:264-9. [PMID: 17118331 PMCID: PMC2577384 DOI: 10.1016/j.abb.2006.10.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [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: 09/05/2006] [Revised: 09/26/2006] [Accepted: 10/17/2006] [Indexed: 11/19/2022]
Abstract
Laforin, encoded by the EPM2A gene, by sequence is a member of the dual specificity protein phosphatase family. Mutations in the EPM2A gene account for around half of the cases of Lafora disease, an autosomal recessive neurodegenerative disorder, characterized by progressive myoclonus epilepsy. The hallmark of the disease is the presence of Lafora bodies, which contain polyglucosan, a poorly branched form of glycogen, in neurons, muscle and other tissues. Glycogen metabolizing enzymes were analyzed in a transgenic mouse over-expressing a dominant negative form of laforin that accumulates Lafora bodies in several tissues. Skeletal muscle glycogen was increased 2-fold as was the total glycogen synthase protein. However, the -/+glucose-6-P activity of glycogen synthase was decreased from 0.29 to 0.16. Branching enzyme activity was increased by 30%. Glycogen phosphorylase activity was unchanged. In whole brain, no differences in glycogen synthase or branching enzyme activities were found. Although there were significant differences in enzyme activities in muscle, the results do not support the hypothesis that Lafora body formation is caused by a major change in the balance between glycogen elongation and branching activities.
Collapse
Affiliation(s)
- Wei Wang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5122
| | - Hannes Lohi
- Indiana University Center for Diabetes Research, The Hospital for Sick Children, Toronto
| | - Alexander V. Skurat
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5122
| | - Anna A. DePaoli-Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5122
| | - Berge A. Minassian
- Indiana University Center for Diabetes Research, The Hospital for Sick Children, Toronto
| | - Peter J. Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5122
- ¶Correspondence to: Peter J. Roach, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5122, Phone 317 274-1582, FAX 317 274-4686, E-mail
| |
Collapse
|
188
|
Franceschetti S, Gambardella A, Canafoglia L, Striano P, Lohi H, Gennaro E, Ianzano L, Veggiotti P, Sofia V, Biondi R, Striano S, Gellera C, Annesi G, Madia F, Civitelli D, Rocca FE, Quattrone A, Avanzini G, Minassian B, Zara F. Clinical and Genetic Findings in 26 Italian Patients with Lafora Disease. Epilepsia 2006; 47:640-3. [PMID: 16529633 DOI: 10.1111/j.1528-1167.2006.00479.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [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: 11/29/2022]
Abstract
PURPOSE EPM2B mutations have been found in a variable proportion of patients with Lafora disease (LD). Genotype-phenotype correlations suggested that EPM2B patients show a slower course of the disease, with delayed age at death, compared with EPM2A patients. We herein report clinical and genetic findings of 26 Italian LD patients. METHODS Disease progression was evaluated by means of a disability scale based on residual motor and cognitive functions and daily living and social abilities, at 4 years from the onset. Mutational analysis was performed by sequencing the coding regions of the EPM2A and EPM2B genes. RESULTS Age at onset ranged from 8.5 to 18.5 years (mean, 13.7+/-2.6). The mean duration of follow-up was 7.1+/-3.9 years. Daily living activities and social interactions were preserved in five of 24 patients. The remaining patients showed moderate to extremely severe limitations of daily living and social abilities. Sixteen (72%) of 22 families showed mutations in the EPM2B gene, and five (22%), in the EPM2A gene. One family showed no mutations. A novel EPM2B mutation also was identified. CONCLUSIONS In our series, EPM2B mutations occurred in 72% of families, thus indicating that EPM2B is the major gene for LD in the Italian population. Moreover, we found that six of 17 EPM2B patients preserved daily living activities and social interactions at 4 years from onset, suggesting a slow disease progression. Additional clinical and functional studies will clarify whether specific mutations may influence the course of the disease in LD patients.
Collapse
Affiliation(s)
- Silvana Franceschetti
- Department of Clinical Neurophysiology, Istituto Nazionale Neurologico C. Besta, Milan, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
189
|
Lohi H, Chan EM, Scherer SW, Minassian BA. On the road to tractability: the current biochemical understanding of progressive myoclonus epilepsies. Adv Neurol 2006; 97:399-415. [PMID: 16383151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- Hannes Lohi
- Program in Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
190
|
Turnbull J, Lohi H, Kearney JA, Rouleau GA, Delgado-Escueta AV, Meisler MH, Cossette P, Minassian BA. Sacred disease secrets revealed: the genetics of human epilepsy. Hum Mol Genet 2005; 14 Spec No. 2:2491-2500. [PMID: 16278970] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
Neurons throughout the brain suddenly discharging synchronously and recurrently cause primarily generalized seizures. Discharges localized awhile in one part of the brain cause focal-onset seizures. A genetically determined generalized hyperexcitability had been predicted in primarily generalized seizures, but surprisingly the first epilepsy gene discovered, CHRNA4, was in a focal (frontal lobe)-onset syndrome. Another surprise with CHRNA4 was its encoding of an ion channel present throughout the brain. The reason why CHRNA4 causes focal-onset seizures is unknown. Recently, the second focal (temporal lobe)-onset epilepsy gene, LGI1 (unknown function), was discovered. CHRNA4 led the way to mutation identifications in 15 ion channel genes, most causing primarily generalized epilepsies. Potassium channel mutations cause benign familial neonatal convulsions. Sodium channel mutations cause generalized epilepsy with febrile seizures plus or, if more severe, severe myoclonic epilepsy of infancy. Chloride and calcium channel mutations are found in rare families with the common syndromes childhood absence epilepsy and juvenile myoclonic epilepsy (JME). Mutations in the EFHC1 gene (unknown function) occur in other rare JME families, and yet in other families, associations are present between JME (or other generalized epilepsies) and single nucleotide polymorphisms in the BRD2 gene (unknown function) and the malic enzyme 2 (ME2) gene. Hippocrates predicted the genetic nature of the 'sacred' disease. Genes underlying the 'malevolent' forces seizing 1% of humans have now been revealed. These, however, still account for a mere fraction of the genetic contribution to epilepsy. Exciting years are ahead, in which the genetics of this extremely common, and debilitating, neurological disorder will be solved.
Collapse
Affiliation(s)
- Julie Turnbull
- Program in Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | | | | | | | | | | | | | | |
Collapse
|
191
|
Lohi H, Ianzano L, Zhao XC, Chan EM, Turnbull J, Scherer SW, Ackerley CA, Minassian BA. Novel glycogen synthase kinase 3 and ubiquitination pathways in progressive myoclonus epilepsy. Hum Mol Genet 2005; 14:2727-36. [PMID: 16115820 DOI: 10.1093/hmg/ddi306] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Lafora progressive myoclonus epilepsy, caused by defective laforin or malin, insidiously present in normal teenagers with cognitive decline, followed by rapidly intractable epilepsy, dementia and death. Pathology reveals neurodegeneration with neurofibrillary tangle formation and Lafora bodies (LBs). LBs are deposits of starch-like polyglucosans, insufficiently branched and hence insoluble glycogen molecules resulting from glycogen synthase (GS) overactivity relative to glycogen branching enzyme activity. We previously made the unexpected observation that laforin, in the absence of which polyglucosans accumulate, specifically binds polyglucosans. This suggested that laforin's role is to detect polyglucosan appearances during glycogen synthesis and to initiate mechanisms to downregulate GS. Glycogen synthase kinase 3 (GSK3) is the principal inhibitor of GS. Dephosphorylation of GSK3 at Ser 9 activates GSK3 to inhibit GS through phosphorylation at multiple sites. Glucose-6-phosphate is a potent allosteric activator of GS. Glucose-6-phosphate levels are high when the amount of glucose increases and its activation of GS overrides any phospho-inhibition. Here, we show that laforin is a GSK3 Ser 9 phosphatase, and therefore capable of inactivating GS through GSK3. We also show that laforin interacts with malin and that malin is an E3 ubiquitin ligase that binds GS. We propose that laforin, in response to appearance of polyglucosans, directs two negative feedback pathways: polyglucosan-laforin-GSK3-GS to inhibit GS activity and polyglucosan-laforin-malin-GS to remove GS through proteasomal degradation.
Collapse
Affiliation(s)
- Hannes Lohi
- Program in Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada M5G 1X8
| | | | | | | | | | | | | | | |
Collapse
|
192
|
Raevaara TE, Korhonen MK, Lohi H, Hampel H, Lynch E, Lönnqvist KE, Holinski-Feder E, Sutter C, McKinnon W, Duraisamy S, Gerdes AM, Peltomäki P, Kohonen-Ccorish M, Mangold E, Macrae F, Greenblatt M, de la Chapelle A, Nyström M. Functional significance and clinical phenotype of nontruncating mismatch repair variants of MLH1. Gastroenterology 2005; 129:537-49. [PMID: 16083711 DOI: 10.1016/j.gastro.2005.06.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Accepted: 03/24/2005] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Germline mutations in mismatch repair genes are associated with hereditary nonpolyposis colorectal cancer. A significant proportion of mutations are nontruncating and associated with a variability of clinical phenotype and microsatellite instability and with occasional presence of residual protein in tumor tissue that suggests impaired functional activity but not total lack of mismatch repair. To address pathogenic significance and mechanism of pathogenicity, we studied the functionality of 31 nontruncating MLH1 mutations found in clinically characterized colorectal cancer families and 3 other variations listed in a mutation database. METHODS Mutations constructed by site-directed mutagenesis were studied for protein expression/stability, subcellular localization, protein-protein interaction, and repair efficiency. The genetic and biochemical data were correlated with clinical data. Finally, comparative sequence analysis was performed to assess the value of sequence homology as a tool for predicting functional results. RESULTS Altogether, 22 mutations were pathogenic in more than one assay, 2 variants were impaired in one assay, and 10 variants acted like wild-type protein. Twenty of 34 mutations affected the quantity of MLH1 protein, whereas only 15 mainly amino-terminal mutations were defective in an in vitro repair assay. Comparative sequence analysis correctly predicted functional studies for 82% of variants. CONCLUSIONS Pathogenic nontruncating alterations in MLH1 may interfere with different biochemical mechanisms but generally more than one. The severe biochemical defects are mirrored by phenotypic characteristics such as early age at onset and high microsatellite instability, whereas variants with no or mild defects in functionality are associated with variable clinical phenotypes.
Collapse
Affiliation(s)
- Tiina E Raevaara
- Department of Biological and Environmental Sciences, University of Helsinki, Finland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
193
|
Turnbull J, Lohi H, Kearney JA, Rouleau GA, Delgado-Escueta AV, Meisler MH, Cossette P, Minassian BA. Sacred disease secrets revealed: the genetics of human epilepsy. Hum Mol Genet 2005; 14:2491-500. [PMID: 16049035 DOI: 10.1093/hmg/ddi250] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Neurons throughout the brain suddenly discharging synchronously and recurrently cause primarily generalized seizures. Discharges localized awhile in one part of the brain cause focal-onset seizures. A genetically determined generalized hyperexcitability had been predicted in primarily generalized seizures, but surprisingly the first epilepsy gene discovered, CHRNA4, was in a focal (frontal lobe)-onset syndrome. Another surprise with CHRNA4 was its encoding of an ion channel present throughout the brain. The reason why CHRNA4 causes focal-onset seizures is unknown. Recently, the second focal (temporal lobe)-onset epilepsy gene, LGI1 (unknown function), was discovered. CHRNA4 led the way to mutation identifications in 15 ion channel genes, most causing primarily generalized epilepsies. Potassium channel mutations cause benign familial neonatal convulsions. Sodium channel mutations cause generalized epilepsy with febrile seizures plus or, if more severe, severe myoclonic epilepsy of infancy. Chloride and calcium channel mutations are found in rare families with the common syndromes childhood absence epilepsy and juvenile myoclonic epilepsy (JME). Mutations in the EFHC1 gene (unknown function) occur in other rare JME families, and yet in other families, associations are present between JME (or other generalized epilepsies) and single nucleotide polymorphisms in the BRD2 gene (unknown function) and the malic enzyme 2 (ME2) gene. Hippocrates predicted the genetic nature of the 'sacred' disease. Genes underlying the 'malevolent' forces seizing 1% of humans have now been revealed. These, however, still account for a mere fraction of the genetic contribution to epilepsy. Exciting years are ahead, in which the genetics of this extremely common, and debilitating, neurological disorder will be solved.
Collapse
Affiliation(s)
- Julie Turnbull
- The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | | | | | | | | | | | | | | |
Collapse
|
194
|
Kujala M, Tienari J, Lohi H, Elomaa O, Sariola H, Lehtonen E, Kere J. SLC26A6 and SLC26A7 Anion Exchangers Have a Distinct Distribution in Human Kidney. ACTA ACUST UNITED AC 2005; 101:e50-8. [PMID: 15956810 DOI: 10.1159/000086345] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Accepted: 03/16/2005] [Indexed: 01/12/2023]
Abstract
BACKGROUND The anion transporters SLC26A6 (PAT1) and SLC26A7, transporting at least chloride, oxalate, sulfate and bicarbonate, show a distinct expression and function in different mammalian species. They are expressed in kidney, but their exact localization in human kidney has not been studied. We therefore examined SLC26A6 and A7 expression in human kidneys. METHODS The localization of SLC26A6 and A7 in different segments of human nephrons was studied by RT-PCR and immunohistochemistry by comparing to the tubular markers PNRA, CD10, Tamm-Horsfall antigen, high molecular weight cytokeratin, CK7, AQP2 and H(+)V-ATPase. RESULTS In human kidney, SLC26A6 is expressed in distal segments of proximal tubules, parts of the thin and thick ascending limbs of Henle's loops, macula densa, distal convoluted tubules and a subpopulation of intercalated cells of collecting ducts. SLC26A7 is expressed in extraglomerular mesangial cells and a subpopulation of intercalated cells of collecting ducts. CONCLUSION Our results show that in human kidney SLC26A6 and A7 have a distinct, partially overlapping expression in distal segments of nephrons. The distribution partly differs from that found previously in rodent kidneys.
Collapse
Affiliation(s)
- Minna Kujala
- Department of Medical Genetics, University of Helsinki, Helsinki, Finland.
| | | | | | | | | | | | | |
Collapse
|
195
|
Abdel-Rahman WM, Lohi H, Knuutila S, Peltomäki P. Restoring mismatch repair does not stop the formation of reciprocal translocations in the colon cancer cell line HCA7 but further destabilizes chromosome number. Oncogene 2005; 24:706-13. [PMID: 15580308 DOI: 10.1038/sj.onc.1208129] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
An important anticarcinogenic function of the mismatch repair (MMR) system is its role in preventing recombination between similar, but nonidentical (homeologous) sequences, thus preventing chromosomal rearrangements. We recently identified a novel chromosomal instability (CIN) phenotype in an MMR defective colon cancer cell line (HCA7) characterized by an ongoing tendency to multiple reciprocal chromosomal translocations. To analyse the relation between MMR and chromosomal changes more closely, the HCA7 stem clone was divided into three stocks. The first was stably transfected with MLH1 expression plasmid, the second was regularly exposed to the demethylating agent 5-azacytidin to re-express the hypermethylated MLH1 gene, and the third was an unmanipulated control stock. All stocks were propagated in vitro for 55-80 passages and, furthermore, some of the early passages were irradiated to induce DNA double-strand breaks. Multiplex-fluorescent in situ hybridization (M-FISH) analysis showed that all three stocks acquired varying numbers of reciprocal translocations and other structural changes at some point. Interestingly, the control stock, which is MMR defective, maintained its numerical chromosomal stability, while some of the MMR-proficient clones showed additional numerical instability. Although the control stock was less sensitive to irradiation, its surviving clones showed marked stability of chromosome structure and number compared to the MMR-competent stocks. These results show that restoring MMR does not prevent the development of reciprocal translocations but rather predisposes cells to numerical CIN after irradiation. Thus, the accumulating data suggest that MMR defect may not be necessary for the development of reciprocal chromosomal translocations but might be permissive.
Collapse
|
196
|
Lohi H, Young EJ, Fitzmaurice SN, Rusbridge C, Chan EM, Vervoort M, Turnbull J, Zhao XC, Ianzano L, Paterson AD, Sutter NB, Ostrander EA, André C, Shelton GD, Ackerley CA, Scherer SW, Minassian BA. Expanded Repeat in Canine Epilepsy. Science 2005; 307:81. [PMID: 15637270 DOI: 10.1126/science.1102832] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Epilepsy afflicts 1% of humans and 5% of dogs. We report a canine epilepsy mutation and evidence for the existence of repeat-expansion disease outside humans. A canid-specific unstable dodecamer repeat in the Epm2b (Nhlrc1) gene recurrently expands, causing a fatal epilepsy and contributing to the high incidence of canine epilepsy. Tracing the repeat origins revealed two successive events, starting 50 million years ago, unique to canid evolution. A genetic test, presented here, will allow carrier and presymptomatic diagnosis and disease eradication. Clinicopathologic characterization establishes affected animals as a model for Lafora disease, the most severe teenage-onset human epilepsy.
Collapse
Affiliation(s)
- Hannes Lohi
- The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
197
|
Ianzano L, Zhang J, Chan EM, Zhao XC, Lohi H, Scherer SW, Minassian BA. Lafora progressive myoclonus epilepsy mutation database-EPM2A and NHLRC1 (EMP2B) genes. Hum Mutat 2005; 26:397. [PMID: 16134145 DOI: 10.1002/humu.9376] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Progressive Myoclonus Epilepsy (PME) of the Lafora type is an autosomal recessive disease, which presents in teenage years with myoclonia and generalized seizures leading to death within a decade of onset. It is characterized by pathognomonic inclusions, Lafora bodies (LB), in neurons and other cell types. Two genes causing Lafora disease (LD), EPM2A on chromosome 6q24 and NHLRC1 (EPM2B) on chromosome 6p22.3 have been identified, and our recent results indicate there is at least one other gene causing the disease. The EPM2A gene product, laforin, is a protein tyrosine phosphatase (PTP) with a carbohydrate-binding domain (CBD) in the N-terminus. NHLRC1 encodes a protein named malin, containing a zinc finger of the RING type in the N-terminal half and 6 NHL-repeat domains in the C-terminal direction. To date 43 different variations in EPM2A and 23 in NHLRC1 are known, including missense, nonsense, frameshift, and deletions. We have developed a human LD mutation database using a new generic biological database cross-referencing platform. The database, which currently contains 66 entries is accessible on the World Wide Web (http://projects.tcag.ca/lafora). Entries can be submitted via the curator of the database or via a web-based form.
Collapse
Affiliation(s)
- Leonarda Ianzano
- Department of Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
198
|
Renkonen E, Lohi H, Järvinen HJ, Mecklin JP, Peltomäki P. Novel splicing associations of hereditary colon cancer related DNA mismatch repair gene mutations. J Med Genet 2004; 41:e95. [PMID: 15235038 PMCID: PMC1735832 DOI: 10.1136/jmg.2003.017269] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- E Renkonen
- Department of Medical Genetics, FIN-00014 University of Helsinki, Finland
| | | | | | | | | |
Collapse
|
199
|
Chernova MN, Jiang L, Friedman DJ, Darman RB, Lohi H, Kere J, Vandorpe DH, Alper SL. Functional comparison of mouse slc26a6 anion exchanger with human SLC26A6 polypeptide variants: differences in anion selectivity, regulation, and electrogenicity. J Biol Chem 2004; 280:8564-80. [PMID: 15548529 DOI: 10.1074/jbc.m411703200] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [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: 01/12/2023] Open
Abstract
The unusually low 78% amino acid identity between the orthologous human SLC26A6 and mouse slc26a6 polypeptides prompted systematic comparison of their anion transport functions in Xenopus oocytes. Multiple human SLC26A6 variant polypeptides were also functionally compared. Transport was studied as unidirectional fluxes of (36)Cl(-), [(14)C]oxalate, and [(35)S]sulfate; as net fluxes of HCO(3)(-) by fluorescence ratio measurement of intracellular pH; as current by two-electrode voltage clamp; and as net Cl(-) flux by fluorescence intensity measurement of relative changes in extracellular and intracellular [Cl(-)]. Four human SLC26A6 polypeptide variants each exhibited rates of bidirectional [(14)C]oxalate flux, Cl(-)/HCO(3)(-) exchange, and Cl(-)/OH(-) exchange nearly equivalent to those of mouse slc26a6. Cl(-)/HCO(3)(-) exchange by both orthologs was cAMP-sensitive, further enhanced by coexpressed wild type cystic fibrosis transmembrane regulator but inhibited by cystic fibrosis transmembrane regulator DeltaF508. However, the very low rates of (36)Cl(-) and [(35)S]sulfate transport by all active human SLC26A6 isoforms contrasted with the high rates of the mouse ortholog. Human and mouse orthologs also differed in patterns of acute regulation. Studies of human-mouse chimeras revealed cosegregation of the high (36)Cl(-) transport phenotype with the transmembrane domain of mouse slc26a6. Mouse slc26a6 and human SLC26A6 each mediated electroneutral Cl(-)/HCO(3)(-) and Cl(-)/OH(-) exchange. In contrast, whereas Cl(-)/oxalate exchange by mouse slc26a6 was electrogenic, that mediated by human SLC26A6 appeared electroneutral. The increased currents observed in oocytes expressing either mouse or human ortholog were pharmacologically distinct from the accompanying monovalent anion exchange activities. The human SLC26A6 polypeptide variants SLC26A6c and SLC26A6d were inactive as transporters of oxalate, sulfate, and chloride. Thus, the orthologous mouse and human SLC26A6 proteins differ in anion selectivity, transport mechanism, and acute regulation, but both mediate electroneutral Cl(-)/HCO(3)(-) exchange.
Collapse
Affiliation(s)
- Marina N Chernova
- Molecular and Vascular Medicine Unit and Renal Unit, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215, USA
| | | | | | | | | | | | | | | |
Collapse
|
200
|
Chan EM, Ackerley CA, Lohi H, Ianzano L, Cortez MA, Shannon P, Scherer SW, Minassian BA. Laforin preferentially binds the neurotoxic starch-like polyglucosans, which form in its absence in progressive myoclonus epilepsy. Hum Mol Genet 2004; 13:1117-29. [PMID: 15102711 DOI: 10.1093/hmg/ddh130] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Lafora disease (LD) is a fatal and the most common form of adolescent-onset progressive epilepsy. Fulminant endoplasmic reticulum (ER)-associated depositions of starch-like long-stranded, poorly branched glycogen molecules [known as polyglucosans, which accumulate to form Lafora bodies (LBs)] are seen in neuronal perikarya and dendrites, liver, skeletal muscle and heart. The disease is caused by loss of function of the laforin dual-specificity phosphatase or the malin E3 ubiquitin ligase. Towards understanding the pathogenesis of polyglucosans in LD, we generated a transgenic mouse overexpressing inactivated laforin to trap normal laforin's unknown substrate. The trap was successful and LBs formed in liver, muscle, neuronal perikarya and dendrites. Using immunogold electron microscopy, we show that laforin is found in close proximity to the ER surrounding the polyglucosan accumulations. In neurons, it compartmentalizes to perikaryon and dendrites and not to axons. Importantly, it binds polyglucosans, establishing for the first time a direct association between the disease-defining storage product and disease protein. It preferentially binds polyglucosans over glycogen in vivo and starch over glycogen in vitro, suggesting that laforin's role begins after the appearance of polyglucosans and that the laforin pathway is involved in monitoring for and then preventing the formation of polyglucosans. In addition, we show that the laforin interacting protein, EPM2AIP1, also localizes on the polyglucosan masses, and we confirm laforin's intense binding to LBs in human LD biopsy material.
Collapse
Affiliation(s)
- Elayne M Chan
- The Hospital for Sick Children and Department of Molecular and Medical Genetics, the University of Toronto, Toronto, Canada
| | | | | | | | | | | | | | | |
Collapse
|