Causes of Williams Syndrome

Unless one of the parents is a carrier of Williams Syndrome themselves, it is not passed on to the child. Still the condition the parents are in may impact whether or not pieces are deleted. The older the parents get, the greater the chance a genetic disorder will occur. Also, if either partner has a history of chromosomal abnormality or are carriers of a recessive gene, their chances of having a child with a genetic disorder again increase. 1 in 10,000 people are diagnosed with Williams Syndrome worldwide, and about 20-30,000 are diagnosed  in the US. Williams Syndrome is found equally in  men and women. Individuals with Williams Syndrome are usually the only ones in their family who carry the disease.  The deletion happens as the baby is forming, and is not due to (or passed down by) the parent. If, for instance, the parents had another child, the chance for that child to have Williams Syndrome would be near nonexistent because the deletion does not occur in the parent, but in the forming fetus. On the other hand, if the person with Williams Syndrome decided to have a child, the chance of passing the deleted piece of chromosome on is about 50%.