Life expectancy is less than that of the general population, mostly due to the increased rates of heart disease. Signs and symptoms
The most common symptoms of Williams syndrome are heart defects and unusual facial features. Other symptoms include failure to gain weight appropriately in infancy (failure to thrive) and low muscle tone. People with WS tend to have widely spaced teeth, a long philtrum, and a flattened nasal bridge.Most people with WS are highly verbal relative to their intelligence, and are often very sociable, having what has been described as a "cocktail party"-type personality. People with Williams syndrome hyperfocus on the eyes of others in social engagements. Physical
People with WS experience many cardiac problems, commonly heart murmurs and the narrowing of major blood vessels, as well as supravalvular aortic stenosis. Other symptoms may include gastrointestinal problems, such as severe or prolonged colic, abdominal pain and diverticulitis, nocturnal enuresis (bed wetting) and urinary difficulties, dental irregularities and defective tooth enamel, and hormone problems, the most common being hypercalcemia. Hypothyroidism has been reported to occur in children, although no proof has been found of it occurring in adults; adults with WS have a higher risk of developing type-2 diabetes, with some cases apparent as young as 21 years old.People with WS often have hyperacusia and phonophobia, which resembles noise-induced hearing loss, but this may be due to a malfunctioning auditory nerve. People with WS can also tend to demonstrate a love of music, and they appear significantly more likely to possess absolute pitch.
Also, higher prevalences of left-handedness and left-eye dominance seem to occur.Ophthalmologic issues are common in WS. Up to 75% of subjects in some studies have strabismus (ocular misalignment), particularly esotropia, due to inherent subnormal binocular visual function
and cognitive deficits in visuospatial construction. People with WS have problems with visual processing, but this is related to difficulty in dealing with complex spatial relationships rather than depth perception per se. Nervous system
Because of missing multiple genes, many effects on the brain are seen, including abnormalities in the cerebellum, right parietal lobe, and left frontal cortical regions. This pattern is consistent with the visual-spatial disabilities and problems with behavioral timing often seen in WS.Frontal-cerebellar pathways, involved in behavioral timing, are often abnormally developed in people with WS, which may be related to their deficits in coordination and execution of fine motor tasks such as drawing and writing. In addition, people with WS often exhibit gross motor difficulties, including trouble walking downstairs,  overactive motor reflexes (hyperreflexia), and hyperactive, involuntary movement of the eyes (nystagmus).Williams syndrome is also noteworthy for exhibiting abnormalities in the parietal-dorsal areas of the neocortex, but not the ventral areas. The parietal-dorsal area handles visual processing that supports visual-spatial analysis of the environment, while the ventral is related to semantic recognition of visual stimuli, and the recognition of faces.