CPT® Code 81240

The CPT® Code 81240 pertains to molecular genetic testing specifically aimed at identifying a mutation in the F2 gene, which encodes for prothrombin, a crucial coagulation factor in the blood clotting process. This particular test focuses on the 20210G>A variant, a well-documented single nucleotide polymorphism that results in a change from guanine to adenine at nucleotide position 20210. This autosomal dominant mutation is significant as it leads to elevated levels of plasma prothrombin, which can increase the risk of thrombotic events. The prevalence of this variant is approximately 2% within the Caucasian population in the United States, with a higher occurrence noted among individuals of southern European descent. Importantly, this genetic variant affects both genders equally and is not restricted to any specific blood type. In the context of inheritance, the presence of just one mutated copy of the gene (heterozygous state) can predispose individuals to various forms of thrombosis, including venous thrombosis in the extremities, cerebral regions, and intra-abdominal areas, as well as arterial thrombosis leading to serious conditions such as myocardial infarction and stroke. Although it is less common, individuals can inherit two mutated copies of the gene (homozygous state), which may further increase their risk. Additionally, women carrying this mutation, whether in a heterozygous or homozygous state, face heightened risks when using oral contraceptives, including the potential for deep vein thrombosis and adverse pregnancy outcomes such as miscarriage and placental complications. Therefore, molecular genetic testing for the F2 gene mutation is particularly indicated for women with histories of infertility or fetal loss, as well as for both men and women who have experienced thrombotic events like deep vein thrombosis, pulmonary embolism, or premature cardiovascular incidents.