Detection of an atypical 7q11.23 deletion in Williams syndrome patients which does not include the STX1A and FZD3 genes

We present two patients with the full Williams syndrome (WS) phenotype carr ying a smaller deletion than typically observed. The deleted region spans f rom the elastin gene to marker P7S1870, This observation narrows the minima l region of deletion in WS and suggests that the syntaxin 1A and frizzled g enes are not responsible for the major features of this developmental disor der and provides important insight into understanding the genotype-phenotyp e correlation in WS.