Williams syndrome (Williams–Beuren syndrome) is a rare neurodevelopmental disorder characterized by mental retardation, hypercalcemia of infants, heart defects, characteristic facial features ("elfin" facial appearance) and failure to thrive. It is caused by a deletion on chromosome 7.
The clinical features of Williams syndrome are manifold and include the following.
Other clinical features in these patients include:
Diagnosis of Williams syndrome is made on the basis of the following :
Being a genetic defect, Williams syndrome does not have a cure. Symptomatic treatment is, however, possible. Cardiac, visual, gastrointestinal and urinary system and orthopedic abnormalities should be thoroughly assessed and treated accordingly.
The patients should be treated on the basis of their particular tendency for music to placate them and relieve the anxiety and phobias. Surgical interventions for cardiovascular or ocular complications might be required   . Genetic counseling of parents should be done.
Mortality rate due to Williams syndrome is high due to cardiovascular complications. However, most of the patients lead healthy life and live to an old age.
Deletion of a cascade (approximately more than 25) of genes from the long arm of chromosome 7 (q11.23) resulting in gene haplodeficiency is the underlying etiology of Williams syndrome. The gene defect is usually acquired, occurring in the eggs or sperms during their formation. The genes most commonly deleted are:
The incidence of the disease is approximately 1 in 7,500 to 20,000 live births. Most of the cases of the disease are sporadic. The incidence of the disease is equal among the males and females. Symptoms of the disease vary among different races. Chinese populations are more prone to cardiovascular complications whereas Greek populations have low incidence of cardiovascular system abnormalities.
The gene deletions include the deletion of ELN gene that encodes for the protein elastin which is a part of many of the connective tissues including the arterial walls. Loss of elastin results in connective tissue abnormalities in many of the body viscera predominantly in the heart. Pulmonary and aortic valvular stenoses are common manifestations. The loss of elastin manifests in the integumentary system as fullness of the cheeks. Vocal cords are also affected causing hoarseness of voice. Diverticuli are common, especially in the bladder.
Loss of GTF2I, GTF2IRD1 and LIMK1 genes result in visual as well as spatial defects. Deletion of CLIP2 gene results in behavioral changes associated with the disease (eg. irritability) as well as cognitive defects. The deletion or overexpression of NCF1 gene has been linked to the risk of hypertension in people with Williams syndrome. Recent studies have implicated familial inversion polymorphism in the region of chromosome 7 as an underlying cause of Williams syndrome.
Prenatal screening for gene abnormalities is helpful in genetic and anticipatory counseling of the parents and in the management of this condition. Lifelong monitoring of the patients with Williams syndrome should be ensured.
Williams syndrome, also known as Beuren syndrome or Elfin Facies syndrome is a rare disorder that arises due to gene defect. The distinctive features of the disease include characteristic facial features and congenital cardiovascular problems .
Individuals with Williams syndrome are quite sociable and have a cheery demeanor but are unable to form lasting relationships as they are unable to understand the subtleties involved in social interactions. Development delay and cognitive defects are also common in these patients.
Williams syndrome is a gene defect that gives rise to a particular set of symptoms in the patients. The individuals have characteristic facial features including low set nose and wide tip of nose, wide mouth and a broad forehead. The patients have low intelligence levels but have particular fondness for music. Developmental milestones are achieved quite late. Difficulty in coordinated movements like drawing is also faced. Hearing and visual defects are also common. Heart problems are widely observed in these patients.
No cure is available for this disease. The patients can be monitored for heart defects. Such individuals mostly lead a long healthy life but heart abnormalities may become the cause of death.