An autosomal genomic screen for autism

Autism is a severe neurodevelopmental disorder defined by social and commun ication deficits and ritualistic-repetitive behaviors that are detectable i n early childhood. The etiology of idiopathic autism is strongly genetic, a nd oligogenic transmission is likely. The first stage of a two-stage genomi c screen for autism was carried out by the Collaborative Linkage Study of A utism on individuals affected with autism from 75 families ascertained thro ugh an affected sib-pair. The strongest multipoint results were for regions on chromosomes 13 and 7. The highest maximum multipoint heterogeneity LOD (MMLS/het) score is 3.0 at D13S800 (approximately 55 cM from the telomere) under the recessive model, with an estimated 35% of families linked to this locus. The next highest peak is an MMLS/het score of 2.3 at 19 cM, between D13S217 and D13S1229. Our third highest MMLS/het score of 2.2 is on chromo some 7 and is consistent with the International Molecular Genetic Study of Autism Consortium report of a possible susceptibility locus somewhere withi n 7q31-33. These regions and others will be followed up in the second stage of our study by typing additional markers in both the original and a secon d set of identically ascertained autism families, which are currently being collected. By comparing results across a number of studies, we expect to b e able to narrow our search for autism susceptibility genes to a small numb er of genomic regions. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:609-6 15, 1999. (C) 1999 Wiley-Liss, Inc.