Williams syndrome is caused by the spontaneous deletion of 26-28 genes on one copy of chromosome #7. The deletion occurs at the time of conception and is not caused by anything parents did or did not do either before or during pregnancy.
Williams syndrome is caused by the spontaneous deletion of 26-28 genes on one copy of chromosome #7. The deletion occurs at the time of conception and is not caused by anything parents did or did not do either before or during pregnancy.