Newbury, D, Warburton, P, Wilson, N, Bacchelli, E, Carone, S, Lamb, J, Maestrini,
E, Volpi, E, Mohammed, S, Baird, G, Monaco, A,
Am J Med Genet A. 2009;149(4):588-597.
Autism is a neurodevelopmental disorder characterized by deficits in reciprocal social
interaction and communication, and repetitive and stereotyped behaviors and interests.
Previous genetic studies of autism have shown evidence of linkage to chromosomes 2q,
3q, 7q, 11p, 16p, and 17q. However, the complexity and heterogeneity of the disorder
have limited the success of candidate gene studies. It is estimated that 5% of the
autistic population carry structural chromosome abnormalities. This article describes
the molecular cytogenetic characterization of two chromosome 2q deletions in unrelated
individuals, one of whom lies in the autistic spectrum. Both patients are affected
by developmental disorders with language delay and communication difficulties. Previous
karyotype analyses described the deletions as [46,XX,del(2)(q24.1q24.2)dn]. Breakpoint
refinement by FISH mapping revealed the two deletions to overlap by approximately
1.1Mb of chromosome 2q24.1, a region which contains just one gene-potassium inwardly
rectifying channel, subfamily J, member 3 (KCNJ3). However, a mutation screen of this
gene in 47 autistic probands indicated that coding variants in this gene are unlikely
to underlie the linkage between autism and chromosome 2q. Nevertheless, it remains
possible that variants in the flanking genes may underlie evidence of linkage at this
locus. (c) 2009 Wiley-Liss, Inc.