Direct duplication of 9p22→p24 in a child with duplication 9p syndrome

A de novo direct duplication of 9p22→p24 was shown in a child with a duplication 9p phenotype by GTG banding and fluorescence in situ hybridization (FISH) using a chromosome-9 specific painting probe as well as 6 YAC DNA probes localized to the 9p13–9p23 region. The breakpoints in this patient and previously reported patients suggest that 9p22 may be the critical region for duplication 9p syndrome. Am. J. Med. Genet. 77:268–271, 1998. © 1998 Wiley-Liss, Inc.