I Government Agencies Genetic Disorders Genetic disorders may be influenced by several factors. When a disease runs in a family, faulty genes are passed from parent to child. Mutations may also appear during fetal development. In these cases, children with genetic abnormalities may be born to parents without genetic disorders. The major types of genetic disorders are described below.
Chromosomal disorders are abnormalities in the number or structure of the chromosomes.
These disorders are often severe and include mental retardation and a variety of physical deformities. Examples include Down syndrome, Turner syndrome, and Klinefelter syndrome. Most of these are rare, but together they cause significant illness. They may vary greatly in severity and may not produce symptoms until late in life. While children in these cases may suffer genetic disease, both parents will be healthy because their defective genes are paired with normal copies.