Routine cytogenetic and FISH studies for 17p11/15q11 duplications and subtelomeric rearrangement studies in children with autism spectrum disorders

To assess the frequency of cytogenetic abnormalities in children with autism spectrum disorders (ASDs), routine G‐banded cytogenetic analyses and FISH studies to rule out 15q11.2 and 17p11.2 duplications were performed on 49 children with ASDs. Blood samples were further studied using a complete set of subtelomeric FISH probes. Routine chromosome study showed that one child had a small duplication of chromosome 5: 46,XY,dup(5)(p?14.2p?15.1). Another child had an interstitial duplication of the Prader‐Willi and Angelman syndrome critical region of chromosome 15, detected by FISH analysis. The detection of these two cases underscores the importance of obtaining routine chromosome and 15q11‐q13 FISH analyses in children with ASDs. No instance of 17p11.2 duplication was observed. Subtelomeric analysis did not reveal abnormalities in any of the subjects. © 2003 Wiley‐Liss, Inc.