A Diagnosis to Consider in an Adult Patient with Facial Features and Intellectual Disability: Williams Syndrome.

Williams syndrome (OMIM #194050) is a rare, well-recognized, multisystemic genetic condition affecting approximately 1/7,500 individuals. There are no marked regional differences in the incidence of Williams syndrome. The syndrome is caused by a hemizygous deletion of approximately 28 genes, including on chromosome 7q11.2. Prenatal-onset growth retardation, distinct facial appearance, cardiovascular abnormalities, and unique hypersocial behavior are among the most common clinical features. Here, we report the case of a patient referred to us with distinct facial features and intellectual disability, who was diagnosed with Williams syndrome at the age of 37 years. Our aim is to increase awareness regarding the diagnostic features and complications of this recognizable syndrome among adult health care providers. Williams syndrome is usually diagnosed during infancy or childhood, but in the absence of classical findings, such as cardiovascular anomalies, hypercalcemia, and cognitive impairment, the diagnosis could be delayed. Due to the multisystemic and progressive nature of the syndrome, accurate diagnosis is critical for appropriate care and screening for the associated morbidities that may affect the patient's health and well-being.