The physical signs that often indicate a suspected case of WS include puffiness around the eyes, a long philtrum, and a stellate pattern in the iris. Physiological symptoms that often contribute to a WS diagnosis are cardiovascular problems, particularly aortic or pulmonary stenosis, and feeding disturbance in infants. Developmental delays are often taken as an initial sign of the syndrome, as well.If a physician suspects a case of WS, the diagnosis is confirmed using one of two possible genetic tests: Micro-array analysis or the fluorescent in situ hybridization test, which examines chromosome 7 and probes for the existence of two copies of the elastin gene. Since 98-99% of individuals with WS lack half of the 7q11.23 region of chromosome 7, where the elastin gene is located, the presence of only one copy of the gene is a strong sign of WS. This confirmatory genetic test has been validated in epidemiological studies  and has been demonstrated to be a more effective method of identifying WS than previous methods, which often relied on the presence of cardiovascular problems and facial features (which, while common, are not always present).Reliance on facial features to identify WS may cause a misdiagnosis of the condition. Among the more reliable features suggestive of WS are congenital heart disease, periorbital fullness ("puffy" eyes), and the presence of a long, smooth philtrum. Less reliable signs of the syndrome include anteverted nostrils, a wide mouth, and an elongated neck.
One of the things to be careful of with this approach is to make sure that the patients charming nature does not mask any underlying feelings.Perhaps the most effective treatment for those with WS is music. Those affected have shown relative strength in regards to music, albeit only in pitch and rhythm tasks. Not only do they show strength in the field, but also a particular fondness for it. Music may help with the internal and external anxiety with which these people are more likely to be afflicted. Notably, the typical person processes music in the superior temporal and middle temporal gyri. Those with WS have reduced activation in these areas, but an increase in the right amygdala and cerebellum.People affected by WS are supported by multiple organizations, including the Canadian Association for Williams Syndrome and the Williams Syndrome Registry. Epidemiology
Williams syndrome has historically been estimated to occur in roughly one in every 20,000 live births, but  more recent epidemiological studies have placed the occurrence rate at closer to one in every 7,500 live births, a significantly larger prevalence. As increasing evidence suggests WS is more common than originally noted (about 6% of all genetic cases of developmental disability), researchers have begun to theorize past underdiagnosis of the syndrome.