The phenotype is variable, likely depending upon the size of the deletion.  Cardiovascular disease, primarily hypertension and large vessel stenosis, are among the most important features.  The elastin arteriopathy lead to thickened arterial walls with peripheral pulmonary stenosis and supravalvular aortic stenosis.  The facies is considered unique with bitemporal narrowing, a wide mouth, full lips, malocclusion, small jaw, and prominent earlobes.  The teeth are small and widely spaced.  Connective tissue abnormalities include joint hyperextensibility, hernias, lax skin, hypotonia, and bowel/bladder diverticulae.  Small birth size is common and infants often fail to thrive but at puberty patients can experience a growth spurt.  Ultimate height in adults is usually in the third centile.

Vocal cord anomalies and paralysis can result in a hoarse voice.  A sensorineural hearing loss is common among adults but hyperacusis is often present in young children.

Hypercalcemia and hypercalciuria are common and some (10%) have hypothyroidism.

Most individuals have some cognition difficulties and delays but normal intelligence has also been reported.  Patient personalities consist of anxiety, attention deficit disorder, marked friendliness and a high level of empathy.  Visiospatial construction is often impaired.  Most adults are unable to live independently.