SEGREGATION ANALYSIS OF ATTENTION-DEFICIT HYPERACTIVITY DISORDER

Although family, twin and adoption studies suggest that genetic factors are involved in attention deficit hyperactivity disorder, further evidence is needed to demonstrate that its familial transmission is consistent with known genetic mechanisms. We applied segregation analysis to a sample of 257 children and their 808 first-degree relatives. Interviews of subjects with DSM-III-R-based structured interviews provided the basis for psychiatric diagnosis. We analyzed these family data with the mixed model, as implemented in the computer program POINTER and a Class A regressive logistic model as implemented in the computer program REGTL. Our results indicate that the familial distribution of DSM-III-R attention deficit hyperactivity disorder is consistent with the effects of a single major gene. We can reject multifactorial polygenic transmission, non-familial environmental transmission, and cultural transmission.