WSS

Williams syndrome, also known as Williams-Beuren syndrome, is a rare genetic disorder characterized by growth delays before and after birth (prenatal and postnatal growth retardation), short stature, a varying degree of mental deficiency, and distinctive facial features that typically become more pronounced with age. Such characteristic facial features may include a round face, full cheeks, thick lips, a large mouth that is usually held open, and a broad nasal bridge with nostrils that flare forward (anteverted nares)...In most individuals with Williams syndrome, the disorder appears to occur spontaneously for unknown reasons (sporadically). However, familial cases have also been reported. Sporadic and familial cases are thought to result from deletion of genetic material from adjacent genes (contiguous genes) within a specific region of chromosome 7 (7q11.23). (Source: National Organization for Rare Disorders)