Williams syndrome is a rare genetic disorder that results in cognitive and psychological problems, according to MedicineNet. People with this disorder are very friendly and gregarious, but they also may suffer from learning disabilities, phobias, anxiety and attention deficit disorder.
People with Williams syndrome often have distinctive facial features that have been described as elfin-like, says the National Organization for Rare Disorders. They may also have problems with their teeth, which may be too small and crowded. They are at risk for cardiovascular and connective tissue diseases, according to MedicineNet, and may also develop aortic stenosis and hypercalcemia. The former is a disorder where the aortic valve is too narrow, and the latter means the levels of calcium in the blood are too high, claims Mayo Clinic.
Williams syndrome is a genetic disease, according to the National Organization for Rare Disorders. It usually appears spontaneously; however, in some cases it is inherited. Scientists believe that Williams syndrome is caused by an incomplete chromosome 7. In spontaneous cases, gene deletion during cell division may be responsible for the anomaly. In familial cases, the incomplete chromosome can be inherited from either parent. Because the defect only has to occur in the chromosome of one parent for symptoms to appear, Williams syndrome is an autosomal dominant disease.