Williams-Beuren syndrome(WBS) is a genetic disease characterized by distinct facial features,short stature,hypotonia, mental retardation,overfriendly and hyper-social behavior, congenital heart disease,infantile hypercalcemia,arterial hypertension and other variable clinical manifestations in organs and systems such as the kidneys,eyes,gastrointestinal and osteoarticular systems(Morris and Mervis,2000).This mental retardation syndrome occurs in 1/20,000 live births(Meyer-Lindenberg et al.,2006).It is caused by a 1.55-1.84 Mb Williams-Beuren syndrome (WBS) is a genetic disease characterized by distinct facial features, short stature, hypotonia, mental retardation, overfriendly and hyper-social behavior, congenital heart disease, infantile hypercalcemia, arterial hypertension and other variable clinical manifestations in organs and systems such as the kidneys, eyes, gastrointestinal and osteoarticular systems (Morris and Mervis, 2000). This mental retardation syndrome occurs in 1 / 20,000 live births (Meyer-Lindenberg et al., 2006). It is caused by a 1.55-1.84 Mb