Independent replication and initial fine mapping of 3p21-24 in Asperger syndrome.

Background: Asperger syndrome is characterised by abnormalities in social interaction as well as repetitive and stereotyped behaviours and interests. The trait is thought to display complex inheritance, but in a subset of families the inheritance resembles the autosomal dominant model. Linkage to 3p14 - 24 has recently been reported in Asperger syndrome in Finnish families with a maximum multipoint NPLall of 3.32 at D3S2432. Methods: We have replicated linkage findings to 3p21 - 24 in 12 new extended Asperger syndrome families. Linkage analyses were performed separately for the 12 new families, and linkage and association analyses were also performed jointly with data from the original genome- wide screen. Results: Best two point and multipoint logarithm of the odds (LOD) scores in analyses of both data sets were obtained at D3S2432 (NPLall = 3.83) with both subsets of families contributing to linkage. Association analysis of the combined data set produced a trend towards association with D3S2432 and D3S1619. Conclusions: This study further validates 3q21 - 24 as a candidate region for Asperger syndrome.