Most cases of Down syndrome are not genetic, with only 1 percent of cases considered hereditary, according to the National Down Syndrome Society. The remaining 99 percent of cases are random. One of every 691 babies born yearly has the disease.Continue Reading
There are some known factors that can increase the risk that a child will be born with Down syndrome, including a mother that is age 35 or older. Women who have at least one child with the disease are more likely to have another child born with it.
Translocation is a form of Down syndrome that does carry a higher risk of development due to genetics. One third of this type are hereditary.Learn more about Conditions & Diseases