1
|
Kessi M, Duan H, Xiong J, Chen B, He F, Yang L, Ma Y, Bamgbade OA, Peng J, Yin F. Attention-deficit/hyperactive disorder updates. Front Mol Neurosci 2022; 15:925049. [PMID: 36211978 PMCID: PMC9532551 DOI: 10.3389/fnmol.2022.925049] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 08/26/2022] [Indexed: 11/15/2022] Open
Abstract
Background Attention-deficit/hyperactive disorder (ADHD) is a neurodevelopmental disorder that commonly occurs in children with a prevalence ranging from 3.4 to 7.2%. It profoundly affects academic achievement, well-being, and social interactions. As a result, this disorder is of high cost to both individuals and society. Despite the availability of knowledge regarding the mechanisms of ADHD, the pathogenesis is not clear, hence, the existence of many challenges especially in making correct early diagnosis and provision of accurate management. Objectives We aimed to review the pathogenic pathways of ADHD in children. The major focus was to provide an update on the reported etiologies in humans, animal models, modulators, therapies, mechanisms, epigenetic changes, and the interaction between genetic and environmental factors. Methods References for this review were identified through a systematic search in PubMed by using special keywords for all years until January 2022. Results Several genes have been reported to associate with ADHD: DRD1, DRD2, DRD4, DAT1, TPH2, HTR1A, HTR1B, SLC6A4, HTR2A, DBH, NET1, ADRA2A, ADRA2C, CHRNA4, CHRNA7, GAD1, GRM1, GRM5, GRM7, GRM8, TARBP1, ADGRL3, FGF1, MAOA, BDNF, SNAP25, STX1A, ATXN7, and SORCS2. Some of these genes have evidence both from human beings and animal models, while others have evidence in either humans or animal models only. Notably, most of these animal models are knockout and do not generate the genetic alteration of the patients. Besides, some of the gene polymorphisms reported differ according to the ethnic groups. The majority of the available animal models are related to the dopaminergic pathway. Epigenetic changes including SUMOylation, methylation, and acetylation have been reported in genes related to the dopaminergic pathway. Conclusion The dopaminergic pathway remains to be crucial in the pathogenesis of ADHD. It can be affected by environmental factors and other pathways. Nevertheless, it is still unclear how environmental factors relate to all neurotransmitter pathways; thus, more studies are needed. Although several genes have been related to ADHD, there are few animal model studies on the majority of the genes, and they do not generate the genetic alteration of the patients. More animal models and epigenetic studies are required.
Collapse
Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Haolin Duan
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Juan Xiong
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Yanli Ma
- Department of Neurology, Children’s Hospital Affiliated to Zhengzhou University, Henan Children’s Hospital, Zhengzhou Children’s Hospital, Zhengzhou, China
| | - Olumuyiwa A. Bamgbade
- Department of Anesthesiology and Pharmacology, University of British Columbia, Vancouver, BC, Canada
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
- *Correspondence: Fei Yin,
| |
Collapse
|
2
|
Zhu K, Liu Q, Xie X, Jiang Q, Feng Y, Xiao P, Wu X, Zhu B, Song R. Interaction between manganese and SLC6A3 genetic polymorphisms in relation to dyslexia. Neurotoxicology 2022; 92:102-109. [DOI: 10.1016/j.neuro.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 07/11/2022] [Accepted: 08/04/2022] [Indexed: 12/09/2022]
|
3
|
Saha S, Chatterjee M, Shom S, Sinha S, Mukhopadhyay K. Functional SLC6A3 polymorphisms differentially affect autism spectrum disorder severity: a study on Indian subjects. Metab Brain Dis 2022; 37:397-410. [PMID: 34845656 DOI: 10.1007/s11011-021-00876-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/14/2021] [Indexed: 10/19/2022]
Abstract
Imbalance in dopamine (DA) signaling is proposed to play a potential role in the etiology of Autism spectrum disorder (ASD) since, as a neuromodulator, DA regulates executive function, motor activity, social peering, attention as well as perception and subjects with ASD often exhibit deficit in these traits. Level of DA in the synaptic cleft is maintained by dopamine transporter (DAT) and hence, to identify the role of DAT in ASD, we have analyzed four functional genetic variants, rs28363170, rs3836790, rs2652511, rs27072, in nuclear families with ASD probands. Subjects were diagnosed based on Diagnostic and Statistical Manual for Mental Disorders and trait severity was assessed by Childhood Autism Rating Scale 2-Standard test. Informed written consent was obtained from the parents/care givers before recruitment followed by collection of peripheral blood for genomic DNA isolation. Target sites were investigated by PCR-based methods and data obtained was analyzed by population- as well as family-based statistical methods. Case-control analysis revealed significant higher frequencies of 9 repeat (9R) and 5 repeat (5R) alleles of rs28363170 and rs3836790 respectively in the ASD probands. Family-based analysis showed statistically significant higher paternal transmission of rs28363170 9R and rs2652511 T alleles. In the presence of rs28363170 9R, rs27072 C, rs3836790 6R6R, and rs2652511 CC variants, trait scores were higher. Studied variants showed independent as well as interactive effects, which varied based on gender of the probands. We infer that altered DA availability mediated through DAT may affect autistic traits warranting further in depth investigation in the field.
Collapse
Affiliation(s)
- Sharmistha Saha
- Manovikas Biomedical Research and Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector J, EM Bypass, Kolkata, West Bengal, 700107, India
| | - Mahasweta Chatterjee
- Manovikas Biomedical Research and Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector J, EM Bypass, Kolkata, West Bengal, 700107, India
| | - Sayanti Shom
- Manovikas Biomedical Research and Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector J, EM Bypass, Kolkata, West Bengal, 700107, India
| | - Swagata Sinha
- Manovikas Biomedical Research and Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector J, EM Bypass, Kolkata, West Bengal, 700107, India
| | - Kanchan Mukhopadhyay
- Manovikas Biomedical Research and Diagnostic Centre, Manovikas Kendra, 482 Madudah, Plot I-24, Sector J, EM Bypass, Kolkata, West Bengal, 700107, India.
| |
Collapse
|
4
|
Children's DAT1 Polymorphism Moderates the Relationship Between Parents' Psychological Profiles, Children's DAT Methylation, and Their Emotional/Behavioral Functioning in a Normative Sample. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16142567. [PMID: 31323798 PMCID: PMC6678924 DOI: 10.3390/ijerph16142567] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 12/19/2022]
Abstract
Parental psychopathological risk is considered as one of the most crucial features associated with epigenetic modifications in offspring, which in turn are thought to be related to their emotional/behavioral profiles. The dopamine active transporter (DAT) gene is suggested to play a significant role in affective/behavioral regulation. On the basis of the previous literature, we aimed at verifying whether children’s DAT1 polymorphisms moderated the relationship between parents’ psychological profiles, children’s emotional/behavioral functioning, and DAT1 methylation in a normative sample of 79 families with school-age children (Ntot = 237). Children’s biological samples were collected through buccal swabs, while Symptom Check-List-90 item Revised, Adult Self Report, and Child Behavior Check-List/6–18 was administered to assess parental and children’s psychological functioning. We found that higher maternal externalizing problems predicted the following: higher levels of children’s DAT1 methylation at M1, but only among children with 10/10 genotype; higher levels of methylation at M2 among children with 10/10 genotype; while lower levels for children with a 9-repeat allele. There was also a positive relationship between fathers’ externalizing problems and children’s externalizing problems, only for children with a 9-repeat allele. Our findings support emerging evidence of the complex interplay between genetic and environmental factors in shaping children’ emotional/behavioral functioning, contributing to the knowledge of risk variables for a child’s development and psychological well-being.
Collapse
|
5
|
Drury SS, Brett ZH, Henry C, Scheeringa M. The association of a novel haplotype in the dopamine transporter with preschool age posttraumatic stress disorder. J Child Adolesc Psychopharmacol 2013; 23:236-43. [PMID: 23647133 PMCID: PMC3657285 DOI: 10.1089/cap.2012.0072] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Significant evidence supports a genetic contribution to the development of posttraumatic stress disorder (PTSD). Three previous studies have demonstrated an association between PTSD and the nine repeat allele of the 3' untranslated region (3'UTR) variable number tandem repeat (VNTR) in the dopamine transporter (DAT, rs28363170). Recently a novel, functionally significant C/T single-nucleotide polymorphism (SNP) in the 3'UTR (rs27072) with putative interactions with the 3'VNTR, has been identified. To provide enhanced support for the role of DAT and striatal dopamine regulation in the development of PTSD, this study examined the impact of a haplotype defined by the C allele of rs27072 and the nine repeat allele of the 3'VNTR on PTSD diagnosis in young trauma-exposed children. METHODS DAT haplotypes were determined in 150 trauma-exposed 3-6 year-old children. PTSD was assessed with a semistructured interview. After excluding double heterozygotes, analysis was performed on 143 total subjects. Haplotype was examined in relation to categorical and continuous measures of PTSD, controlling for trauma type and race. Additional analysis within the two largest race categories was performed, as other means of controlling for ethnic stratification were not available. RESULTS The number of haplotypes (0, 1, or 2) defined by the presence of the nine repeat allele of rs28363170 (VNTR in the 3'UTR) and the C allele of rs27072 (SNP in the 3'UTR) was significantly associated with both the diagnosis of PTSD and total PTSD symptoms. Specifically, children with one or two copies of the haplotype had significantly more PTSD symptoms and were more likely to be diagnosed with PTSD than were children without this haplotype. CONCLUSIONS These findings extend previous findings associating genetic variation in the DAT with PTSD. The association of a haplotype in DAT with PTSD provides incremental traction for a model of genetic vulnerability to PTSD, a specific underlying mechanism implicating striatal dopamine regulation, and insight into potential future personalized interventions.
Collapse
Affiliation(s)
- Stacy S Drury
- Department of Psychiatry and Behavioral Sciences, Tulane University School of Medicine, New Orleans, LA 70112, USA.
| | | | | | | |
Collapse
|
6
|
Abstract
The ability to inhibit unwanted actions is a heritable executive function that may confer risk to disorders such as attention deficit hyperactivity disorder (ADHD). Converging evidence from pharmacology and cognitive neuroscience suggests that response inhibition is instantiated within frontostriatal circuits of the brain with patterns of activity that are modulated by the catecholamines dopamine and noradrenaline. A total of 405 healthy adult participants performed the stop-signal task, a paradigmatic measure of response inhibition that yields an index of the latency of inhibition, termed the stop-signal reaction time (SSRT). Using this phenotype, we tested for genetic association, performing high-density single-nucleotide polymorphism mapping across the full range of autosomal catecholamine genes. Fifty participants also underwent functional magnetic resonance imaging to establish the impact of associated alleles on brain and behaviour. Allelic variation in polymorphisms of the dopamine transporter gene (SLC6A3: rs37020; rs460000) predicted individual differences in SSRT, after corrections for multiple comparisons. Furthermore, activity in frontal regions (anterior frontal, superior frontal and superior medial gyri) and caudate varied additively with the T-allele of rs37020. The influence of genetic variation in SLC6A3 on the development of frontostriatal inhibition networks may represent a key risk mechanism for disorders of behavioural inhibition.
Collapse
|
7
|
Elia J, Sackett J, Turner T, Schardt M, Tang SC, Kurtz N, Dunfey M, McFarlane NA, Susi A, Danish D, Li A, Nissley-Tsiopinis J, Borgmann-Winter K. Attention-deficit/hyperactivity disorder genomics: update for clinicians. Curr Psychiatry Rep 2012; 14:579-89. [PMID: 22843546 DOI: 10.1007/s11920-012-0309-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Attention deficit, hyperactivity disorder (ADHD) is familial and highly heritable. Several candidate genes involved in neurotransmission have been identified, however these confer minimal risk, suggesting that for the most part, ADHD is not caused by single common genetic variants. Advances in genotyping enabling investigation at the level of the genome have led to the discovery of rare structural variants suggesting that ADHD is a genomic disorder, with potentially thousands of variants, and common neuronal pathways disrupted by numerous rare variants resulting in similar ADHD phenotypes. Heritability studies in humans also indicate the importance of epigenetic factors, and animal studies are deciphering some of the processes that confer risk during gestation and throughout the post-natal period. These and future discoveries will lead to improved diagnosis, individualized treatment, cures, and prevention. These advances also highlight ethical and legal issues requiring management and interpretation of genetic data and ensuring privacy and protection from misuse.
Collapse
Affiliation(s)
- Josephine Elia
- Department Psychiatry, The University of Pennsylvania, Philadelphia, PA 19104-6209, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Elia J, Laracy S, Allen J, Nissley-Tsiopinis J, Borgmann-Winter K. Epigenetics: genetics versus life experiences. Curr Top Behav Neurosci 2012; 9:317-340. [PMID: 21728139 DOI: 10.1007/7854_2011_144] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Epigenetics is the field of research that examines alterations in gene expression caused by mechanisms other than changes in DNA sequence. ADHD is highly heritable; however, epigenetics are considered relevant in potentially explaining the variance not accounted for by genetic influence. In this chapter, some of the well-known processes of epigenetics, such as chromosome organization, DNA methylation, and effects of transcriptional factors are reviewed along with studies examining the role of these processes in the pathophysiology of ADHD. Potential epigenetic factors conferring risk for ADHD at various developmental stages, such as alcohol, tobacco, toxins, medications, and psychosocial stressor are discussed. Animal studies investigating ADHD medications and changes in CNS Gene/Protein Expression are also explored since they provide insight into the neuronal pathways involved in ADHD pathophysiology. The current limited data suggest that identification of the epigenetic processes involved in ADHD is extremely important and may lead to potential interventions that may be applied to modify the expression of deleterious, as well as protective, genes.
Collapse
Affiliation(s)
- Josephine Elia
- The Children's Hospital of Philadelphia, Science Center, 3440 Market St, Philadelphia, PA, 19104, USA,
| | | | | | | | | |
Collapse
|
9
|
Schweitzer JB, Fassbender C, Lit L, Reeves GM, Powell SPH. Attention-deficit/hyperactivity disorder. HANDBOOK OF CLINICAL NEUROLOGY 2012; 106:391-405. [PMID: 22608633 DOI: 10.1016/b978-0-444-52002-9.00022-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Julie B Schweitzer
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA, USA.
| | | | | | | | | |
Collapse
|
10
|
Pinsonneault JK, Han DD, Burdick KE, Kataki M, Bertolino A, Malhotra AK, Gu HH, Sadee W. Dopamine transporter gene variant affecting expression in human brain is associated with bipolar disorder. Neuropsychopharmacology 2011; 36:1644-55. [PMID: 21525861 PMCID: PMC3138671 DOI: 10.1038/npp.2011.45] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The gene encoding the dopamine transporter (DAT) has been implicated in CNS disorders, but the responsible polymorphisms remain uncertain. To search for regulatory polymorphisms, we measured allelic DAT mRNA expression in substantia nigra of human autopsy brain tissues, using two marker SNPs (rs6347 in exon 9 and rs27072 in the 3'-UTR). Allelic mRNA expression imbalance (AEI), an indicator of cis-acting regulatory polymorphisms, was observed in all tissues heterozygous for either of the two marker SNPs. SNP scanning of the DAT locus with AEI ratios as the phenotype, followed by in vitro molecular genetics studies, demonstrated that rs27072 C>T affects mRNA expression and translation. Expression of the minor T allele was dynamically regulated in transfected cell cultures, possibly involving microRNA interactions. Both rs6347 and rs3836790 (intron8 5/6 VNTR) also seemed to affect DAT expression, but not the commonly tested 9/10 VNTR in the 3'UTR (rs28363170). All four polymorphisms (rs6347, intron8 5/6 VNTR, rs27072 and 3'UTR 9/10 VNTR) were genotyped in clinical cohorts, representing schizophrenia, bipolar disorder, depression, and controls. Only rs27072 was significantly associated with bipolar disorder (OR = 2.1, p = 0.03). This result was replicated in a second bipolar/control population (OR = 1.65, p = 0.01), supporting a critical role for DAT regulation in bipolar disorder.
Collapse
Affiliation(s)
- Julia K Pinsonneault
- Department of Pharmacology, The Ohio State University, Columbus, OH 43210-1239, USA.
| | - Dawn D Han
- Department of Pharmacology and Program in Pharmacogenomics, The Ohio State University, Columbus, OH, USA
| | - Katherine E Burdick
- Division of Psychiatry Research, The Zucker Hillside Hospital, North Shore-Long Island Jewish Health System and Albert Einstein College of Medicine, New York, NY, USA
| | - Maria Kataki
- Department of Neurology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Alessandro Bertolino
- Psychiatric Neuroscience Group, Department of Neurological and Psychiatric Sciences, University of Bari, Bari, Italy
| | - Anil K Malhotra
- Division of Psychiatry Research, The Zucker Hillside Hospital, North Shore-Long Island Jewish Health System and Albert Einstein College of Medicine, New York, NY, USA
| | - Howard H Gu
- Department of Pharmacology and Program in Pharmacogenomics, The Ohio State University, Columbus, OH, USA
| | - Wolfgang Sadee
- Department of Pharmacology and Program in Pharmacogenomics, The Ohio State University, Columbus, OH, USA
| |
Collapse
|
11
|
Archer T, Oscar-Berman M, Blum K. Epigenetics in Developmental Disorder: ADHD and Endophenotypes. JOURNAL OF GENETIC SYNDROMES & GENE THERAPY 2011; 2:1000104. [PMID: 22224195 PMCID: PMC3250517 DOI: 10.4172/2157-7412.1000104] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Heterogeneity in attention-deficit/hyperactivity disorder (ADHD), with complex interactive operations of genetic and environmental factors, is expressed in a variety of disorder manifestations: severity, co-morbidities of symptoms, and the effects of genes on phenotypes. Neurodevelopmental influences of genomic imprinting have set the stage for the structural-physiological variations that modulate the cognitive, affective, and pathophysiological domains of ADHD. The relative contributions of genetic and environmental factors provide rapidly proliferating insights into the developmental trajectory of the condition, both structurally and functionally. Parent-of-origin effects seem to support the notion that genetic risks for disease process debut often interact with the social environment, i.e., the parental environment in infants and young children. The notion of endophenotypes, markers of an underlying liability to the disorder, may facilitate detection of genetic risks relative to a complex clinical disorder. Simple genetic association has proven insufficient to explain the spectrum of ADHD. At a primary level of analysis, the consideration of epigenetic regulation of brain signalling mechanisms, dopamine, serotonin, and noradrenaline is examined. Neurotrophic factors that participate in the neurogenesis, survival, and functional maintenance of brain systems, are involved in neuroplasticity alterations underlying brain disorders, and are implicated in the genetic predisposition to ADHD, but not obviously, nor in a simple or straightforward fashion. In the context of intervention, genetic linkage studies of ADHD pharmacological intervention have demonstrated that associations have fitted the "drug response phenotype," rather than the disorder diagnosis. Despite conflicting evidence for the existence, or not, of genetic associations between disorder diagnosis and genes regulating the structure and function of neurotransmitters and brain-derived neurotrophic factor (BDNF), associations between symptoms-profiles endophenotypes and single nucleotide polymorphisms appear reassuring.
Collapse
Affiliation(s)
- Trevor Archer
- Department of Psychology, University of Gothenburg, Box 500, SE-40530 Gothenburg, Sweden
| | - Marlene Oscar-Berman
- Departments of Psychiatry, Neurology, and Anatomy & Neurobiology, Boston University School of Medicine, and Boston VA Healthcare System, Boston, MA, USA
| | - Kenneth Blum
- Department of Psychiatry, University of Florida College of Medicine, and McKnight Brain Institute, Gainesville, FL, USA
| |
Collapse
|
12
|
Yeh YW, Lu RB, Tao PL, Shih MC, Lin WW, Huang SY. Neither single-marker nor haplotype analyses support an association between the dopamine transporter gene and heroin dependence in Han Chinese. GENES BRAIN AND BEHAVIOR 2010; 9:638-47. [PMID: 20497233 DOI: 10.1111/j.1601-183x.2010.00597.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Much evidence suggests that dysfunction of dopamine transporter-mediated dopamine transmission may be involved in the pathophysiology of substance abuse and dependence. The aim of this study was to examine whether the dopamine transporter gene (DAT1; SLC6A3) is associated with the development of heroin dependence (HD) and whether DAT1 influences personality traits in patients with HD. Polymorphisms of DAT1 were analyzed in a case-control study of 1046 Han Chinese (615 patients and 431 controls). All participants were screened using a Chinese version of the modified Schedule of Affective Disorder and Schizophrenia-Lifetime and all patients met the criteria for HD. Furthermore, a Chinese version of the Tridimensional Personality Questionnaire (TPQ) was used to assess personality traits in the patient group and examine the association between their personality traits and DAT1 polymorphisms. Of the patient group, 271 completed the TPQ. No statistically significant differences in allele or genotype frequencies of all investigated variants between HD patients and controls were observed. In haplotype analyses, four haplotype blocks of DAT1 were not associated with the development of HD. These DAT1 polymorphisms did not influence novelty seeking and harm avoidance scores in HD patients. This study suggests that the DAT1 gene may not contribute to the risk of HD and specific personality traits in HD among the Han Chinese population.
Collapse
Affiliation(s)
- Y-W Yeh
- Department of Psychiatry, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | | | | | | | | | | |
Collapse
|
13
|
Sharp SI, McQuillin A, Gurling HMD. Genetics of attention-deficit hyperactivity disorder (ADHD). Neuropharmacology 2009; 57:590-600. [PMID: 19715710 DOI: 10.1016/j.neuropharm.2009.08.011] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 08/14/2009] [Accepted: 08/18/2009] [Indexed: 01/15/2023]
Abstract
Attention-deficit hyperactivity disorder (ADHD) is a clinically and genetically heterogeneous syndrome which is comorbid with childhood conduct disorder, alcoholism, substance abuse, dis-social personality disorder, and affective disorders. A small but consistent overlap with autistic symptoms has also been established. Twin and family studies of ADHD show a substantial genetic heritability with little or no family environmental effect. Linkage and association studies have conclusively implicated the dopamine transporter gene (DAT1). DAT1 has also been confirmed as being associated with bipolar disorder. Remarkably, and for the first time in psychiatry, genetic markers at the DAT1 locus appear to be able to predict clinical heterogeneity because the non-conduct disordered subgroup of ADHD is associated with DAT1 whereas other subgroups do not appear to be associated. The second most well replicated susceptibility gene encodes the DRD4 dopamine receptor and many other dopamine related genes appear to be implicated. It is becoming increasingly clear that genes causing bipolar mania overlap with genes for a subtype of ADHD. The key to understanding the genetics of ADHD is to accept very considerable heterogeneity with different genes having effects in different families and in different individuals. It is too early to interpret the new wave of genome-wide association and copy number variant studies but preliminary data support the overlap with affective disorder genes and also with CNS connectivity genes likely to be involved in autism and affective disorders.
Collapse
Affiliation(s)
- Sally I Sharp
- Molecular Psychiatry Laboratory, Research Department of Mental Health Sciences, Windeyer Institute of Medical Sciences, University College London Medical School, 46 Cleveland Street, London W1T 4JF, UK
| | | | | |
Collapse
|
14
|
Roe BE, Tilley MR, Gu HH, Beversdorf DQ, Sadee W, Haab TC, Papp AC. Financial and psychological risk attitudes associated with two single nucleotide polymorphisms in the nicotine receptor (CHRNA4) gene. PLoS One 2009; 4:e6704. [PMID: 19693267 PMCID: PMC2724734 DOI: 10.1371/journal.pone.0006704] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Accepted: 07/21/2009] [Indexed: 11/19/2022] Open
Abstract
With recent advances in understanding of the neuroscience of risk taking, attention is now turning to genetic factors that may contribute to individual heterogeneity in risk attitudes. In this paper we test for genetic associations with risk attitude measures derived from both the psychology and economics literature. To develop a long-term prospective study, we first evaluate both types of risk attitudes and find that the economic and psychological measures are poorly correlated, suggesting that different genetic factors may underlie human response to risk faced in different behavioral domains. We then examine polymorphisms in a spectrum of candidate genes that affect neurotransmitter systems influencing dopamine regulation or are thought to be associated with risk attitudes or impulsive disorders. Analysis of the genotyping data identified two single nucleotide polymorphisms (SNPs) in the gene encoding the alpha 4 nicotine receptor (CHRNA4, rs4603829 and rs4522666) that are significantly associated with harm avoidance, a risk attitude measurement drawn from the psychology literature. Novelty seeking, another risk attitude measure from the psychology literature, is associated with several COMT (catechol-O-methyl transferase) SNPs while economic risk attitude measures are associated with several VMAT2 (vesicular monoamine transporter) SNPs, but the significance of these associations did not withstand statistical adjustment for multiple testing and requires larger cohorts. These exploratory results provide a starting point for understanding the genetic basis of risk attitudes by considering the range of methods available for measuring risk attitudes and by searching beyond the traditional direct focus on dopamine and serotonin receptor and transporter genes.
Collapse
Affiliation(s)
- Brian E Roe
- Department of Agricultural, Environmental and Development Economics, Ohio State University, Columbus, Ohio, USA.
| | | | | | | | | | | | | |
Collapse
|
15
|
Stam AJ, Schothorst PF, Vorstman JA, Staal WG. The genetic overlap of attention deficit hyperactivity disorder and autistic spectrum disorder. APPLICATION OF CLINICAL GENETICS 2009; 2:7-13. [PMID: 23776346 PMCID: PMC3681037 DOI: 10.2147/tacg.s4683] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Autistic spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD) are classified as distinct disorders within the DSM-IV-TR (1994). The manual excludes simultaneous use of both diagnoses in case of overlap on a symptomatic level. However this does not always represent clinical observations and findings of previous studies. This review explores the genetic basis of the phenomenological overlap between ADHD and ASD. Based on an extensive review of twin-, linkage-, association studies, and reported structural genomic abnormalities associated with these disorders, we have identified seventeen regions on the human genome that can be related to both disorders. These regions of shared genetic association are: 2q35, 3p14, 4p16.1, 4p16.3, 5p15.31, 5p15.33, 7p12.3, 7p22, 7q21, 8q24.3, 14q12, 15q11–12, 16p13, 17q11, 18q21–23, 22q11.2, Xp22.3. The presented data are of interest for future genetic studies and appear to suggest the existence of a phenotype partition that may differ from the current classification of psychiatric disorders.
Collapse
Affiliation(s)
- Arie J Stam
- University Medical Center Utrecht (UMC Utrecht), Utrecht, The Netherlands
| | | | | | | |
Collapse
|