Periventricular nodular heterotopia and Williams syndrome.

We report here on the first case of a child with bilateral periventricular nodular heterotopia (PNH) and Williams syndrome. Fluorescent in situ hybridization (FISH) analyses demonstrated a deletion of the elastin gene in the Williams syndrome critical region (WSCR). Further mapping by loss of heterozygosity analysis both by microsatellite marker and SNP profiling demonstrated a 1.5 Mb deletion beyond the telomeric end of the typical WSCR. No mutations were identified in the X-linked filamin-A gene (the most common cause of PNH). These findings suggest another dominant PNH disorder along chromosome 7q11.23. Copyright 2006 Wiley-Liss, Inc.