10.25376/hra.7999358.v1 Jason Karnes Jason Karnes Genetics of HIT_8_30_18_clean.docx Health Research Alliance 2019 Pharmacogenomics heparin-induced thrombocytopenia Heparin Low molecular weight heparin Anticoagulant genome-wide association study Genetics Biomarker Medicine 2019-04-16 15:19:50 Journal contribution https://hra.figshare.com/articles/journal_contribution/Genetics_of_HIT_8_30_18_clean_docx/7999358 <p>Heparin-induced thrombocytopenia (HIT) is a life-threatening, immune-mediated adverse reaction to heparin anticoagulants. The inability to predict HIT represents a considerable liability associated with heparin administration. Genetic studies of HIT are challenging due to the scarcity of true HIT cases, potential for misclassification, and many environmental risk factors. Genetic studies have not consistently identified risk alleles for HIT, the production of platelet factor 4 (PF4)/heparin antibodies, nor the thromboembolic complications of HIT. Genes implicated in HIT and PF4/heparin antibody levels include <i>FCGR2A</i>, <i>TDAG8</i>, <i>HLA-DR</i>, and others. Compelling evidence also suggests that the <i>FCGR2A</i> H131R polymorphism is associated with HIT-related thrombosis. There is a need for well-powered, multiethnic studies with laboratory confirmation of HIT, detailed patient- and drug-specific data, and inclusion of both serologic and thromboembolic outcomes. Genomic biomarkers identified from such studies offer the possibility of shifting current clinical practice paradigms from early detection and treatment to prevention.</p>