Dopa decarboxylase gene polymorphisms and attention deficit hyperactivity disorder (ADHD): no evidence for association in the Irish population
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2001Citation:
Z. Hawi, D. Foley, A. Kirley, M. McCarron, M. Fitzgerald and M. Gill, Dopa decarboxylase gene polymorphisms and attention deficit hyperactivity disorder (ADHD): no evidence for association in the Irish population, Molecular Psychiatry, 6, 4, 2001, 420 - 424Download Item:
Dopa decarboxylase gene polymorphisms and attention deficit hyperactivity disorder (ADHD) - no evidence for association in the Irish population.pdf (Published (publisher's copy) - Peer Reviewed) 119.2Kb
Abstract:
Dopa decarboxylase (DDC) is an enzyme which catalyses the decarboxylation of both dopa to dopamine and L-5 hydroxytryptophan to serotonin. Both catecholamines are major neurotransmitters of the mammalian nervous system. It has been suggested that genes involved in the dopaminergic system play a primary role in predisposing to attention deficit hyperactivity disorder (ADHD). In this study, the 4-bp insertion/deletion variant mapped to the first neuronally expressed exon 1 at the dopa decarboxylase gene and two microsatellite markers flanking the gene were investigated for possible association with ADHD. Using HHRR, we observed an increased transmission (though not significant) of the 4-bp insertion (allele 1) to ADHD cases (chi2 = 2.72, P = 0.1, RR = 1.25). However marginally significant excess transmission of allele 10 (213 bp) of the 3' microsatellite D7S2422 (~0.75 cM distal to dopa decarboxylase gene) was found (chi2 = 4.2, P = 0.04, RR=1.48). Interestingly, a haplotype containing both alleles is transmitted more frequently (chi2= 5, P = 0.025). Analysing data by the sex of transmitting parent showed a greater relative risk for paternal transmission of the 4-bp insertion allele and allele 10 of the D7S2422 (RR = 1.48 and 1.63 respectively). This provides preliminary evidence that this locus or a closely mapped DNA variant may be involved in the genetic susceptibility to ADHD. However, further studies are required to either confirm or refute these observations.
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Health Research Board (HRB)
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http://people.tcd.ie/mgillhttp://people.tcd.ie/mifitzge
http://people.tcd.ie/zhhawi
http://people.tcd.ie/mccarrm
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PUBLISHED(264) PMID: 11443526 ABSTRACT:Dopa decarboxylase (DDC) is an enzyme which catalyses the decarboxylation of both dopa to dopamine and L-5 hydroxytryptophan to serotonin. Both catecholamines are major neurotransmitters of the mammalian nervous system. It has been suggested that genes involved in the dopaminergic system play a primary role in predisposing to attention deficit hyperactivity disorder (ADHD). In this study, the 4-bp insertion/deletion variant mapped to the first neuronally expressed exon 1 at the dopa decarboxylase gene and two microsatellite markers flanking the gene were investigated for possible association with ADHD. Using HHRR, we observed an increased transmission (though not significant) of the 4-bp insertion (allele 1) to ADHD cases (chi(2) = 2.72, P = 0.1, RR = 1.25). However marginally significant excess transmission of allele 10 (213 bp) of the 3' microsatellite D7S2422 ( approximately 0.75 cM distal to dopa decarboxylase gene) was found (chi(2) = 4.2, P = 0.04, RR=1.48). Interestingly, a haplotype containing both alleles is transmitted more frequently (chi(2)= 5, P = 0.025). Analysing data by the sex of transmitting parent showed a greater relative risk for paternal transmission of the 4-bp insertion allele and allele 10 of the D7S2422 (RR = 1.48 and 1.63 respectively). This provides preliminary evidence that this locus or a closely mapped DNA variant may be involved in the genetic susceptibility to ADHD. However, further studies are required to either confirm or refute these observations.
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Molecular Psychiatry6
4
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Full text availableKeywords:
attention deficit hyperactivity disorder (ADHD), dopamine, dopa decarboxylase, association, haplotype based haplotype relative risk (HHRR)Subject (TCD):
Neuroscience , ADD/ADHD , ADD/ADHD , ADHD , ADHD , ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD) , Adolescent Psychiatry , Attention Deficit Hyperactivity Disorder (ADHD) , CHILD PSYCHIATRY , COMMUNITY PSYCHIATRY , CONSULTATION LIAISON PSYCHIATRY , CONSULTATION-LIAISON PSYCHIATRY , DISORDER ADHD , DOPA DECARBOXYLASE , Dopa decarboxylase gene polymorphisms , GENE POLYMORPHISM , GENE POLYMORPHISMS , GENERAL HOSPITAL PSYCHIATRY , LIAISON PSYCHIATRY , Neuropsychiatry , Neuropsychiatry , PSYCHIATRY , Psychiatry , Psychiatry , TRAINEES IN PSYCHIATRY , child and adolescent Psychiatry , neurodevelopmental psychiatryDOI:
http://dx.doi.org/10.1038/sj.mp.4000903Licences: