Genetic testing screens patients as potential carriers of diseases caused by gene mutations. Common genetic tests include screening newborns for genetic disorders and testing patients as carriers of potentially harmful diseases. Testing can also be a tool to estimate a patient’s likelihood of developing a disease, such as cancer.
Genetics and Blood Clotting
A genetic mutation can produce too much of a protein or create an irregularly-shaped protein. Individuals who inherit thrombophilia through a genetic mutation may produce too much or too little of a blood clotting protein, or have their blood clotting protein not function properly. The two most common single nucleotide polymorphisms (SNP’s) responsible for thrombophilia are factor V Leiden and prothrombin G20210A.
The factor V gene codes for the production of the factor V protein. An individual with a mutated factor V gene at position 1691 (G→A) will have less susceptibility to inactivation by activated protein C resulting in excess blot clotting. Prothrombin G20210A (also known as factor II mutation) is a SNP located at the 3’ untranslated region of the prothrombin gene that alters the regulation of prothrombin production. Hence, it will produce more of this protein, resulting in more prothrombin in the circulation system and increased tendency for the blood to clot.
Factor V Leiden and factor II SNP’s are commonly found in Caucasian populations, with about 2-4% of people affected worldwide. In the United States, African Americans, Native Americans, and Asian Americans are rarely affected.