Detection of chromosome aberrations in Chinese children with autism using G-banding and BAC FISH.

OBJECTIVE: To detect the characteristic chromosomal changes in Chinese children with infantile autism. METHODS: Chromosome aberrations in 68 cases of infantile autism were analyzed by high-resolution G-banding and fluorescence in situ hybridization (FISH) with bacterial artificial chromosome (BAC) clones. RESULTS: Chromosomal changes were detected in 4 cases by high-resolution G-banding: one case with t(4;6)(q23-24;p21), one case with longer p arm of chromosome 21 (21p+), and two cases with pericentric inversion of chromosome 9 (inv(9)) which was confirmed by C-banding. BAC FISH analysis was performed to confirm these observations and changes in chromosomes 2, 7 and 15, which are often found in autistic children. There could exist the translocation of t(4;6) (q25-26;p21.1). Chromosome changes often reported previously in chromosomes 2, 7 and 15 were not detected in this study. Inv(9) and 21p+ were not confirmed with present BAC clones. CONCLUSION: Chromosomal changes were detected in four cases of infantile autism, with a detectability of 5.9% , far lower than that (10% to 48%) reported in literature. The breakpoint of translocation could be detected more accurately using BAC FISH method.