1
|
Levy AM, Paschou P, Tümer Z. Candidate Genes and Pathways Associated with Gilles de la Tourette Syndrome-Where Are We? Genes (Basel) 2021; 12:1321. [PMID: 34573303 PMCID: PMC8468358 DOI: 10.3390/genes12091321] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/05/2021] [Accepted: 08/25/2021] [Indexed: 12/21/2022] Open
Abstract
Gilles de la Tourette syndrome (GTS) is a childhood-onset neurodevelopmental and -psychiatric tic-disorder of complex etiology which is often comorbid with obsessive-compulsive disorder (OCD) and/or attention deficit hyperactivity disorder (ADHD). Twin and family studies of GTS individuals have shown a high level of heritability suggesting, that genetic risk factors play an important role in disease etiology. However, the identification of major GTS susceptibility genes has been challenging, presumably due to the complex interplay between several genetic factors and environmental influences, low penetrance of each individual factor, genetic diversity in populations, and the presence of comorbid disorders. To understand the genetic components of GTS etiopathology, we conducted an extensive review of the literature, compiling the candidate susceptibility genes identified through various genetic approaches. Even though several strong candidate genes have hitherto been identified, none of these have turned out to be major susceptibility genes yet.
Collapse
Affiliation(s)
- Amanda M. Levy
- Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, 2600 Glostrup, Denmark;
| | - Peristera Paschou
- Department of Molecular Biology and Genetics, Democritus University of Thrace, 68100 Alexandroupolis, Greece;
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Zeynep Tümer
- Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, 2600 Glostrup, Denmark;
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| |
Collapse
|
2
|
Grünblatt E, Marinova Z, Roth A, Gardini E, Ball J, Geissler J, Wojdacz TK, Romanos M, Walitza S. Combining genetic and epigenetic parameters of the serotonin transporter gene in obsessive-compulsive disorder. J Psychiatr Res 2018; 96:209-217. [PMID: 29102815 DOI: 10.1016/j.jpsychires.2017.10.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 10/13/2017] [Accepted: 10/13/2017] [Indexed: 02/07/2023]
Abstract
While genetic variants have been reported to be associated with obsessive-compulsive disorder (OCD), the small effect sizes suggest that epigenetic mechanisms such as DNA methylation may also be relevant. The serotonin transporter (SLC6A4) gene has been extensively investigated in relation to OCD, since serotonin reuptake inhibitors are the pharmacological treatment of choice for the disorder. The current study set three questions: Firstly, whether the high expressing loci of the SLC6A4 polymorphisms, 5-HTTLPR + rs25531, rs25532 and rs16965628 are associated with family-based (n = 164 trios) and case-control OCD (n = 186, 152, respectively). This was also examined by a meta-analysis. Secondly, whether DNA methylation and RNA levels of the SLC6A4 differ in saliva and blood of a subset of samples from pediatric and adult OCD patients and matched controls. And lastly, whether morning awakening cortisol levels correlate with the above. A meta-analysis confirmed the association of the LA-allele with OCD (OR = 1.21, p = 0.00018), maintaining significance in the early-onset OCD subgroup (OR = 1.21, p = 0.022). There was no association between rs25532 or rs16965628 and OCD. Our preliminary data showed that SLC6A4 DNA methylation levels in an amplicon located at the beginning of the first intron were significantly higher in the saliva of pediatric OCD patients compared to controls and adult patients with OCD, but no alterations in RNA levels or in polymorphism interactions were observed. Morning awakening salivary cortisol levels positively correlated with methylation levels, and negatively correlated with RNA levels. This study further supports the involvement of the SLC6A4 gene in OCD through both genetic and epigenetic mechanisms. This finding needs to be explored further in an independent large sample.
Collapse
Affiliation(s)
- Edna Grünblatt
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Switzerland.
| | - Zoya Marinova
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Alexander Roth
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Elena Gardini
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Juliane Ball
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland
| | - Julia Geissler
- Center of Mental Health, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital of Würzburg, Würzburg, Germany
| | - Tomasz K Wojdacz
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 3, Build. 1230, DK-8000 Aarhus, Denmark; Aarhus Institute of Advanced Studies, Høegh-Guldbergs Gade 6B, DK-8000 Aarhus C, Denmark
| | - Marcel Romanos
- Center of Mental Health, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital of Würzburg, Würzburg, Germany
| | - Susanne Walitza
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Switzerland
| |
Collapse
|
3
|
Yi M, Zhang Y, Wang Y, Su N, Liu S. Association between the polymorphism of C861G (rs6296) in the serotonin 1B receptor gene and Tourette syndrome in Han Chinese people. Asia Pac Psychiatry 2017; 9. [PMID: 26123080 DOI: 10.1111/appy.12196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 05/19/2015] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Clinical, neuroimaging and other studies provided evidence that the dysfunction of the serotonin neurotransmitter system were found in Tourette syndrome (TS). This study is to explore the association between the polymorphism of C861G (rs6296) in HTR1B and TS in Han Chinese people. METHODS Two hundred ninety-nine TS patients (260 TS trios and 39 TS patients) and 388 healthy controls were collected. The genotype of HTR1B C861G was detected using Taqman probes. The case-control study and family-based study was used separately to study association between HTR1B C861G and TS in Han Chinese people. RESULTS In case-control study, no statistically significant difference was found in the distribution of HTR1B C861G polymorphism between TS patients and controls (for genotype: χ2 = 3.408, P = 0.182; for allele: χ2 = 0.395, P = 0.530, OR = 0.934, 95%CI: 0.754-1.156). In family-based study, we observed nonsignificant over-transmission of the G861 allele in HTR1B to TS offspring using the transmission disequilibrium test (TDT), haplotype relative risk (HRR) and haplotype-based HRR (HHRR) (TDT χ2 = 0.410, P = 0.560; HRR = 1.151, χ2 = 0.421, P = 0.517, 95% CI: 0.753-1.759; HHRR = 0.919, χ2 = 0.467, P = 0.495, 95%CI: 0.720-1.172). DISCUSSION Our study suggested that the polymorphism of HTR1B C861G is not a risk factor for TS in Han Chinese population. However, the result should be replicated in larger sample and different population.
Collapse
Affiliation(s)
- Mingji Yi
- Department of Child Health Care, The Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| | - Ying Zhang
- Department of Child Health Care, The Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| | - Yujie Wang
- Clinical Laboratory, Qingdao Municipal Hospital, Qingdao, China
| | - Nailun Su
- Clinical Laboratory, Qingdao Women and Children Medical Health Care Center, Qingdao, China
| | - Shiguo Liu
- Genetic Laboratory, The Affiliated Hospital of Medical College, Qingdao University, Qingdao, China
| |
Collapse
|
4
|
Richer P, Fernandez TV. Tourette Syndrome: Bridging the Gap between Genetics and Biology. MOLECULAR NEUROPSYCHIATRY 2015; 1:156-164. [PMID: 26509143 DOI: 10.1159/000439085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tourette syndrome is a childhood neuropsychiatric disorder, which presents with disruptive motor and vocal tics. The disease also has a high comorbidity with obsessive-compulsive disorder and attention deficit hyperactivity disorder, which may further increase the distress experienced by patients. Current treatments act with varying efficacies in alleviating symptoms, as the underlying biology of the disease is not fully understood to provide precise therapeutic targets. Moreover, the genetic complexity of the disorder presents a substantial challenge to the identification of genetic alterations that contribute to the Tourette's phenotype. Nevertheless, genetic studies have suggested involvement of dopaminergic, serotonergic, glutamatergic, and histaminergic pathways in the pathophysiology of at least some cases. In addition, genetic overlaps with other neuropsychiatric disorders may point toward a shared biology. The findings that are emerging from genetic studies will allow researchers to piece together the underlying components of the disease, in the hopes that a deeper understanding of Tourette's can lead to improved treatments for those affected by it.
Collapse
Affiliation(s)
- Petra Richer
- Sewanee: The University of the South, 735 University Avenue Sewanee, TN 37383
| | - Thomas V Fernandez
- Yale Child Study Center and Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06520
| |
Collapse
|
5
|
Mak L, Streiner DL, Steiner M. Is serotonin transporter polymorphism (5-HTTLPR) allele status a predictor for obsessive-compulsive disorder? A meta-analysis. Arch Womens Ment Health 2015; 18:435-45. [PMID: 25896187 DOI: 10.1007/s00737-015-0526-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 03/17/2015] [Indexed: 12/16/2022]
Abstract
The serotonin transporter polymorphism has been implicated in obsessive-compulsive disorder (OCD). However, molecular genetic association studies have yielded inconsistent results. Variation may be due to lack of OCD subtype classification. The goal of this systematic review is to investigate the association of the S-allele of the serotonin transporter polymorphism with OCD and OCD subtypes. A total of 69 studies were initially found through a systematic search of the literature but only 13 with sufficient information to compute odds ratios were suitable for review. A total of 1991 participants with OCD and their 5-HTTLPR allele status were examined. The primary outcome measures were allele frequency and OCD diagnosis. A full meta-analysis was completed comparing the L- and S-alleles using a random effects model in RevMan 5.2.1. Further, a secondary meta-analysis stratified by sex and late-onset was conducted for S- versus L-allele frequency. In the primary meta-analysis, OCD was not associated with the S-allele of the 5-HTTLPR polymorphism (Z = 0.07, p = 0.94). Moreover, late-onset OCD was not associated with the S-allele (Z = 1.45, p = 0.15). However, when stratified by sex, there is an emerging sex-specific relationship. There was a trending association between the S-allele and OCD status in females (Z = 1.62, p = 0.10) but not in males (Z = 0.69, p = 0.49). The findings provide further support for the need of subtype classification of this heterogeneous disorder. Future studies should clearly examine sex differences and OCD age-of-onset. In particular, emphasis should be placed on the effect of female reproductive milestones on OCD onset and symptom exacerbation.
Collapse
Affiliation(s)
- Lauren Mak
- MiNDS Neuroscience, McMaster University, Hamilton, ON, Canada
| | | | | |
Collapse
|
6
|
|
7
|
The relevance of checking population allele frequencies and Hardy-Weinberg Equilibrium in genetic association studies: the case of SLC6A4 5-HTTLPR polymorphism in a Chinese Han Irritable Bowel Syndrome association study. Immunol Lett 2014; 162:276-8. [PMID: 25151208 DOI: 10.1016/j.imlet.2014.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 08/13/2014] [Indexed: 12/27/2022]
|
8
|
Moya PR, Wendland JR, Rubenstein LM, Timpano KR, Heiman GA, Tischfield JA, King RA, Andrews AM, Ramamoorthy S, McMahon FJ, Murphy DL. Common and rare alleles of the serotonin transporter gene, SLC6A4, associated with Tourette's disorder. Mov Disord 2013; 28:1263-70. [PMID: 23630162 PMCID: PMC3766488 DOI: 10.1002/mds.25460] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 02/02/2013] [Accepted: 03/04/2013] [Indexed: 12/27/2022] Open
Abstract
To evaluate the hypothesis that functionally over-expressing alleles of the serotonin transporter (SERT) gene (solute carrier family 6, member 4, SLC6A4) are present in Tourette's disorder (TD), just as we previously observed in obsessive compulsive disorder (OCD), we evaluated TD probands (N = 151) and controls (N = 858). We genotyped the refined SERT-linked polymorphic region 5-HTTLPR/rs25531 and the associated rs25532 variant in the SLC6A4 promoter plus the rare coding variant SERT isoleucine-to-valine at position 425 (I425V). The higher expressing 5-HTTLPR/rs25531 LA allele was more prevalent in TD probands than in controls (χ(2) = 5.75; P = 0.017; odds ratio [OR], 1.35); and, in a secondary analysis, surprisingly, it was significantly more frequent in probands who had TD alone than in those who had TD plus OCD (Fisher's exact test; P = 0.0006; OR, 2.29). Likewise, the higher expressing LAC haplotype (5-HTTLPR/rs25531/rs25532) was more frequent in TD probands than in controls (P = 0.024; OR, 1.33) and also in the TD alone group versus the TD plus OCD group (P = 0.0013; OR, 2.14). Furthermore, the rare gain-of-function SERT I425V variant was observed in 3 male siblings with TD and/or OCD and in their father. Thus, the cumulative count of SERT I425V becomes 1.57% in OCD/TD spectrum conditions versus 0.15% in controls, with a recalculated, family-adjusted significance of χ(2) = 15.03 (P < 0.0001; OR, 9.0; total worldwide genotyped, 2914). This report provides a unique combination of common and rare variants in one gene in TD, all of which are associated with SERT gain of function. Thus, altered SERT activity represents a potential contributor to serotonergic abnormalities in TD. The present results call for replication in a similarly intensively evaluated sample. © 2013 Movement Disorder Society.
Collapse
Affiliation(s)
- Pablo R Moya
- National Institute of Mental Health-Intramural Research Program, Bethesda, MD, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Paschou P. The genetic basis of Gilles de la Tourette Syndrome. Neurosci Biobehav Rev 2013; 37:1026-39. [DOI: 10.1016/j.neubiorev.2013.01.016] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 01/02/2013] [Accepted: 01/07/2013] [Indexed: 12/18/2022]
|
10
|
Paschou P, Fernandez TV, Sharp F, Heiman GA, Hoekstra PJ. Genetic susceptibility and neurotransmitters in Tourette syndrome. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 112:155-77. [PMID: 24295621 DOI: 10.1016/b978-0-12-411546-0.00006-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Family studies have consistently shown that Tourette syndrome (TS) is a familial disorder and twin studies have clearly indicated a genetic contribution in the etiology of TS. Whereas early segregation studies of TS suggested a single-gene autosomal dominant disorder, later studies have pointed to more complex models including additive and multifactorial inheritance and likely interaction with genetic factors. While the exact cellular and molecular base of TS is as yet elusive, neuroanatomical and neurophysiological studies have pointed to the involvement of cortico-striato-thalamocortical circuits and abnormalities in dopamine, glutamate, gamma-aminobutyric acid, and serotonin neurotransmitter systems, with the most consistent evidence being available for involvement of dopamine-related abnormalities, that is, a reduction in tonic extracellular dopamine levels along with hyperresponsive spike-dependent dopamine release, following stimulation. Genetic and gene expression findings are very much supportive of involvement of these neurotransmitter systems. Moreover, intriguingly, genetic work on a two-generation pedigree has opened new research pointing to a role for histamine, a so far rather neglected neurotransmitter, with the potential of the development of new treatment options. Future studies should be aimed at directly linking neurotransmitter-related genetic and gene expression findings to imaging studies (imaging genetics), which enables a better understanding of the pathways and mechanisms through which the dynamic interplay of genes, brain, and environment shapes the TS phenotype.
Collapse
Affiliation(s)
- Peristera Paschou
- Department of Molecular Biology and Genetics, Democritus University of Thrace, Alexandroupoli, Greece
| | | | | | | | | |
Collapse
|