Abnormalities in the dopaminergic system have been proposed as contributory factors in the development of Attention Deficit Hyperactivity Disorder (ADHD). Recently, we reported preferential transmission of a 148 bp allele of a highly polymorphic microsatellite marker located 18.5 kb from the 5′ end of the DRD5 dopamine receptor on chromosome 4 (Daly et al., 1999). We have now examined this (CA)n repeat with a new study sample consisting of 56 trios (mother, father and affected child) and 2 duos (either parent and affected child), diagnosed according to the DSM - IV criteria. As in our previous sample the microsatellite marker was found to have twelve alleles with the 148 bp allele being the most frequent at 45.7%. HHRR (Haplotype Based Haplotype Relative Risk) showed significant preferential transmission of the 148 bp allele (Chisquare = 4.11, P <0.05). These findings are supported by Tahir et al., (2000), and Barr et al., (2000). Thus, we have replicated our previous findings in a new sample derived from the same population and conclude that DNA variants at or near DRD5 confer risk for the development of ADHD.
|Number of pages||1|
|Journal||American Journal of Medical Genetics Part B: Neuropsychiatric Genetics|
|Publication status||Published - 8 Oct 2001|