Article: Dopamine receptor D4 (DRD4) gene in Han Chinese children with Attention-Deficit/Hyperactivity Disorder (ADHD): Increased prevalence of the 2-repeat allele
| Title | Dopamine receptor D4 (DRD4) gene in Han Chinese children with Attention-Deficit/Hyperactivity Disorder (ADHD): Increased prevalence of the 2-repeat allele |
|---|---|
| Authors | Leung, PWL5 Lee, CC1 Hung, SF1 Ho, TP1 Tang, CP1 Kwong, SL1 Leung, SY2 Yuen, ST2 LiehMak, F2 Oosterlaan, J3 Grady, D4 Harxhi, A4 Ding, YC4 Chi, HC4 Flodman, P4 Schuck, S4 Spence, MA4 Moyzis, R4 Swanson, J4 |
| Issue Date | 2005 |
| Publisher | John Wiley & Sons, Inc. The Journal's web site is located at http://www.interscience.wiley.com/jpages/0148-7299:1/ |
| Citation | American Journal Of Medical Genetics - Neuropsychiatric Genetics, 2005, v. 133 B n. 1, p. 54-56 [How to Cite?] DOI: http://dx.doi.org/10.1002/ajmg.b.30129 |
| Abstract | There is an increased prevalence of the 7-repeat (7R) allele of the dopamine receptor D4 (DRD4) gene in attention-deficit/hyperactivity disorder (ADHD). However, the population prevalence of the 7R allele varies considerably across ethnicity and is very low in Asians. To test whether this 7R allele/ADHD association still held in a Chinese clinical sample, 32 Han Chinese children with a confirmed ADHD diagnosis and normal IQ who were methylphenidate- responders were genotyped. None of them had a DRD4 7R allele. Instead, we observed a significantly increased prevalence of the 2-repeat (2R) allele in this clinical sample (33%) compared to ethnically-matched controls (20%) (χ2(1d.f.) = 5.90, P = 0.015). This approximately 1.65-fold increase of the 2R allele in our probands is close to the observed increase of the 7R allele in European-ancestry ADHD children. Recent genetic studies have indicated that the 2R allele in Asians is likely derived from the 7R allele. Further, available biochemical data indicate that both the 2R and 7R protein have blunted responses to dopamine compared to the 4R protein. Based on these results, we propose that the observed increased prevalence of the 2R allele in our Han Chinese ADHD probands is still consistent with the TR allele hypothesis of ADHD in European-ancestry children. Recent studies have suggested that any variant from the conserved ancestral 4R allele might potentially alter biochemistry/phenotype. We hypothesize that an increased frequency of any non-4R allele may define the association of the DRD4 gene with ADHD that holds across ethnicity. The present findings, however, obtained with a small ADHD sample size, should be replicated. © 2005 Wiley-Liss, Inc. |
| ISSN | 1552-4841 2011 Impact Factor: 3.705 2011 SCImago Journal Rankings: 0.288 |
| DOI | http://dx.doi.org/10.1002/ajmg.b.30129 |
| ISI Accession Number ID | WOS:000226619600010 |
| References | References in Scopus |
| dc.contributor.author | Leung, PWL |
|---|---|
| dc.contributor.author | Lee, CC |
| dc.contributor.author | Hung, SF |
| dc.contributor.author | Ho, TP |
| dc.contributor.author | Tang, CP |
| dc.contributor.author | Kwong, SL |
| dc.contributor.author | Leung, SY |
| dc.contributor.author | Yuen, ST |
| dc.contributor.author | LiehMak, F |
| dc.contributor.author | Oosterlaan, J |
| dc.contributor.author | Grady, D |
| dc.contributor.author | Harxhi, A |
| dc.contributor.author | Ding, YC |
| dc.contributor.author | Chi, HC |
| dc.contributor.author | Flodman, P |
| dc.contributor.author | Schuck, S |
| dc.contributor.author | Spence, MA |
| dc.contributor.author | Moyzis, R |
| dc.contributor.author | Swanson, J |
| dc.date.accessioned | 2010-09-06T09:48:11Z |
| dc.date.available | 2010-09-06T09:48:11Z |
| dc.date.issued | 2005 |
| dc.description.abstract | There is an increased prevalence of the 7-repeat (7R) allele of the dopamine receptor D4 (DRD4) gene in attention-deficit/hyperactivity disorder (ADHD). However, the population prevalence of the 7R allele varies considerably across ethnicity and is very low in Asians. To test whether this 7R allele/ADHD association still held in a Chinese clinical sample, 32 Han Chinese children with a confirmed ADHD diagnosis and normal IQ who were methylphenidate- responders were genotyped. None of them had a DRD4 7R allele. Instead, we observed a significantly increased prevalence of the 2-repeat (2R) allele in this clinical sample (33%) compared to ethnically-matched controls (20%) (χ2(1d.f.) = 5.90, P = 0.015). This approximately 1.65-fold increase of the 2R allele in our probands is close to the observed increase of the 7R allele in European-ancestry ADHD children. Recent genetic studies have indicated that the 2R allele in Asians is likely derived from the 7R allele. Further, available biochemical data indicate that both the 2R and 7R protein have blunted responses to dopamine compared to the 4R protein. Based on these results, we propose that the observed increased prevalence of the 2R allele in our Han Chinese ADHD probands is still consistent with the TR allele hypothesis of ADHD in European-ancestry children. Recent studies have suggested that any variant from the conserved ancestral 4R allele might potentially alter biochemistry/phenotype. We hypothesize that an increased frequency of any non-4R allele may define the association of the DRD4 gene with ADHD that holds across ethnicity. The present findings, however, obtained with a small ADHD sample size, should be replicated. © 2005 Wiley-Liss, Inc. |
| dc.description.nature | Link_to_subscribed_fulltext |
| dc.identifier.citation | American Journal Of Medical Genetics - Neuropsychiatric Genetics, 2005, v. 133 B n. 1, p. 54-56 [How to Cite?] DOI: http://dx.doi.org/10.1002/ajmg.b.30129 |
| dc.identifier.doi | http://dx.doi.org/10.1002/ajmg.b.30129 |
| dc.identifier.epage | 56 |
| dc.identifier.hkuros | 108393 |
| dc.identifier.isi | WOS:000226619600010 |
| dc.identifier.issn | 1552-4841 2011 Impact Factor: 3.705 2011 SCImago Journal Rankings: 0.288 |
| dc.identifier.issue | 1 |
| dc.identifier.openurl | ![]() |
| dc.identifier.pmid | 15578612 |
| dc.identifier.scopus | eid_2-s2.0-19944432137 |
| dc.identifier.spage | 54 |
| dc.identifier.uri | http://hdl.handle.net/10722/88802 |
| dc.identifier.volume | 133 B |
| dc.language | eng |
| dc.publisher | John Wiley & Sons, Inc. The Journal's web site is located at http://www.interscience.wiley.com/jpages/0148-7299:1/ |
| dc.publisher.place | United States |
| dc.relation.ispartof | American Journal of Medical Genetics - Neuropsychiatric Genetics |
| dc.relation.references | References in Scopus |
| dc.rights | American Journal of Medical Genetics Part B: Neuropsychiatric Genetics. Copyright © John Wiley & Sons, Inc. |
| dc.subject.mesh | Adolescent |
| dc.subject.mesh | Alleles |
| dc.subject.mesh | Attention Deficit Disorder with Hyperactivity - genetics |
| dc.subject.mesh | Child |
| dc.subject.mesh | China |
| dc.subject.mesh | Gene Frequency |
| dc.subject.mesh | Genotype |
| dc.subject.mesh | Humans |
| dc.subject.mesh | Male |
| dc.subject.mesh | Minisatellite Repeats - genetics |
| dc.subject.mesh | Receptors, Dopamine D2 - genetics |
| dc.subject.mesh | Receptors, Dopamine D4 |
| dc.title | Dopamine receptor D4 (DRD4) gene in Han Chinese children with Attention-Deficit/Hyperactivity Disorder (ADHD): Increased prevalence of the 2-repeat allele |
| dc.type | Article |
Author Affiliations
- Hong Kong Hospital Authority
- The University of Hong Kong
- Vrije Universiteit Amsterdam
- UC Irvine
- Chinese University of Hong Kong


