An investigation into sub-telomeric deletions of chromosome 22 and pervasive developmental disorders.

Deletions of the sub-telomeric region of chromosome 22 have been associated with mental retardation, developmental delay, and autistic behaviors. This study investigated sub-telomeric anomalies of chromosome 22 using fluorescent in situ hybridization (FISH) probes in 82 subjects diagnosed with autism and atypical autism. No microdeletions were detected in this group. Similar FISH analyses were undertaken on two children with developmental delay, who were ascertained to be ring 22 during routine cytogenetic investigations. One subject was shown to have a microdeletion in the sub-telomeric region tested. Both children met the social and communication cut off for autism on the ADI and but did not meet the cut off for restrictive and repetitive behaviors. Only one of the two children met the criteria for PDD on the ADOS.