Analysis of candidate ADHD genes in 179 Irish ADHD-affected nuclear families indicated a larger odds
ratio for paternal transmission of DRD4, DRD5, DAT1, SERT and TPH2
(OR=2) compared to maternal transmission (OR=1.3). For TH, DDC, SNAP-25 and 5HT1B a trend toward
paternal overtransmission was reported (Hawi
Z et al, 2005). These findings have been challenged (Laurin
N et al, 2007).