What is the cause of Down syndrome?
The additional copy of the 21st chromosome which causes Down syndrome can originate from either the father or the mother. Approximately five percent of the cases have been traced to the father. Who has the highest risk of having a child with Down syndrome? Down syndrome can occur in people of all races and economic levels. Older women have an increased chance of having a child with Down syndrome. A 35–year–old woman has about a one in 400 chance of conceiving a child with Down syndrome, and this chance increases gradually to one in 110 by age 40. At age 45 the incidence becomes approximately one in 35. Since many couples are postponing parenting until later in life, the incidence of Down syndrome conceptions is expected to increase. Therefore, genetic counseling for parents is becoming increasingly important. Still, many healthcare providers are not fully informed about advising their patients about the incidences of Down syndrome, advancements in diagnosis, and the protocols for care
