Autosomal diseases are passed on from parent to child. Whether the gene responsible for the disease is dominant or recessive effects the pattern of inheritance. In dominant diseases, only one dominant gene is necessary to have the disease. Almost all affected people have one dominant and one recessive gene. A parent with one dominant gene and one recessive gene has a fifty percent chance of passing the gene to their offspring. These diseases are very rare.
While in recessive genetic diseases, both parents have to be carriers in order for a child to inherit the disease. People with only one copy of the gene do not have the disease. There is a twenty five percent chance the offspring will inherit the disease if both parents are carriers. There is also a twenty five percent chance that the offspring will be unaffected, and a fifty percent chance of becoming a carrier. Recessive diseases are more common in families that marry first or second cousins. This is because there are many similar genes within a family. Since the genes are very similar there is little variation, thus heightening the risks of an autosomal recessive disease. Cystic Fibrosis and sickle cell anemia are examples of autosomal recessive diseases. Males and females are equally affected.
In class we discussed different circumstances regarding the ethics of DNA testing. It was very interesting to see my classmate’s view on such controversial topics. Personally none of my opinions were incredibly strong because there are so many different people with different needs and reasons for genetic testing that coming up with a statement true for everyone is difficult. This activity allowed us to see the debates going on in science communities on a smaller scale, and how there are so many different ways to see the same topic.