Women over age 35 have an increased risk of giving birth to children with which genetic disorder?

Women over age 35 have an increased risk of giving birth to children with Down syndrome primarily due to the biological processes involved in egg development and the aging of oocytes (eggs). As women age, the likelihood of chromosomal abnormalities in their eggs increases. Down syndrome, also known as trisomy 21, occurs when an individual has an extra copy of chromosome 21, which can result from incorrect cell division during the formation of eggs or sperm.

Research indicates that the risk of having a baby with Down syndrome rises significantly as maternal age increases, particularly for women over 35. This is linked to factors such as the length of time eggs have been in the ovaries and the potential for genetic errors during meiosis, the process that creates eggs.

Other conditions, such as spina bifida, cystic fibrosis, and muscular dystrophy, are influenced by different factors, including genetic inheritance patterns or environmental factors, but they do not show the same strong correlation with maternal age as Down syndrome does. Thus, the increased risk associated with maternal age highlights the specific nature of this genetic disorder compared to others.