Text Box: CLINICAL FEATURES AND GENE DELETIONS OF WILLIAMS SYNDROME Liang Y, Zhou A-Q, Wang S-X, Hu Q Shanghai Institute for Pediatric Research, Shanghai, China Objective: Supravalvular aortic stenosis (SVAS) occurs in three settings: Williams syndrome (WS), autosomal dominant familial cases, and sporadic cases. Most patients with SVAS have WS. WS is a developmental disorder affecting multiple organ systems. This study aimed at discussing the criteria of WS in China by evaluating the clinical features and detecting gene deletions in children believed to have SVAS. Method: Twenty-six children (17 males and 9 females, range 1.1 to19.5) with SVAS were enrolled. Diagnosis of SVAS has been based on physical examination, echocardiography, cardiac catheterization and angiography. The mostly clinical features of WS in these children were assessed according to Lowery¡¯s WS phenotype scoring system, which included typical facial features, mental retardation /developmental delay, SVAS, non-SVAS congenital heart disease, inguinal hernia, and hypercalcemia. All children also underwent an evaluation of minor medical problems of WS, involving WS personality, head circumference, voice, musculoskeletal organ systems and etc.. Fluorescent in situ hybridizations (FISH) were used to detect the microdeletions of elastin (ELN) gene and LIM kinase 1 (LIMK1) gene in all the children. Result: Nineteen children, whose WS phenotype scoring was more than 4, showed the gene microdeletions. Children whose scoring was equal to 4 (n=3) or less than 4 (n=4) did not demonstrate deletions. Conclusion: This data indicated that WS could be diagnosed in children with SVAS whose Lowery¡¯s scoring was more than 4. Microdeletions of ELN gene and LIMK1gene were detected in children with WS. 1166