ABSTRACT: BACKGROUND:Whether disclosing genetic risk for coronary heart disease (CHD) to individuals influences information seeking and information sharing is not known. We hypothesized that disclosing genetic risk for CHD to individuals influences information seeking and sharing. METHODS AND RESULTS:The MI-GENES study (Myocardial Infarction Genes) randomized participants (n=203) aged 45 to 65 years who were at intermediate CHD risk based on conventional risk factors and not on statins to receive their conventional risk score alone or also a genetic risk score based on 28 variants. CHD risk was disclosed by a genetic counselor and then discussed with a physician. Surveys assessing information seeking were completed before and after risk disclosure. Information sharing was assessed post-disclosure. Six-month post-disclosure, genetic risk score participants were more likely than conventional risk score participants to visit a website to learn about CHD (odds ratio [OR], 4.88 [confidence interval (CI), 1.55-19.13]; P=0.01), use the internet for information about how genetic factors affect CHD risk (OR, 2.11 [CI, 1.03-4.47]; P=0.04), access their CHD risk via a patient portal (OR, 2.99 [CI, 1.35-7.04]; P=0.01), and discuss their CHD risk with others (OR, 3.13 [CI, 1.41-7.47]; P=0.01), particularly their siblings (OR, 1.92 [CI, 1.06-3.51]; P=0.03), extended family (OR, 3.8 [CI, 1.37-12.38]; P=0.01), coworkers (OR, 2.42 [CI, 1.09-5.76]; P=0.03), and primary care provider (PCP; OR, 2.00 [CI, 1.08-3.75]; P=0.03). CONCLUSIONS:Disclosure of a genetic risk score for CHD increased information seeking and sharing. CLINICAL TRIAL REGISTRATION:URL: https://clinicaltrials.gov/. Unique identifier: NCT01936675.