The genetics of attention-deficit/hyperactivity disorder.
Attention-deficit/hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder that almost certainly represents the common outcome of multiple causal pathways and it is now generally accepted that genetic factors make a significant contribution to these pathways. Behavioral studies suggest a heritability of approximately 0.76. While molecular genetic approaches have identified a range of potential candidate genes, it is now clear that the genetics of ADHD are characterized by a number of genes each of which makes a small but significant contribution to the overall risk. Several genome-wide linkage studies have been conducted and, although there are considerable differences in findings between studies, several regions have been supported across several studies (bin 16.4, 5p13, 11q22-25, 17p11). The contribution of several candidate genes has been supported by meta-analyses (DRD4, DRD5, DAT1, HTR1B and SNAP25). Genome-wide association scans are starting to appear but have not yet had sufficient power to produce conclusive results. Gene-environment interactions, which are as yet relatively understudied, are likely to be of importance in fully understanding the role of genes in ADHD and will be discussed.
Coghill
David
D
Centre for Neuroscience, Division of Medical Sciences, University of Dundee, Centre for Child Health, 19 Dudhope Terrace, Dundee, DD3 6HH, UK. d.r.coghill@dundee.ac.uk
Banaschewski
Tobias
T
D001289:Attention Deficit Disorder with Hyperactivity / Q000209:etiology / Q000235:genetics*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics; D004777:Environment; D020022:Genetic Predisposition to Disease; D005823:Genetics; D055106:Genome-Wide Association Study / Q000379:methods; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D011954:Receptors, Dopamine / Q000235:genetics / Q000378:metabolism; D044263:Receptors, Serotonin, 5-HT1 / Q000235:genetics; D050825:Synaptosomal-Associated Protein 25 / Q000235:genetics
D050483:Dopamine Plasma Membrane Transport Proteins; D011954:Receptors, Dopamine; D044263:Receptors, Serotonin, 5-HT1; C494208:SNAP25 protein, human; D050825:Synaptosomal-Associated Protein 25