...considerations are influenced by the morphological diversity of HCM and the unpredictable instability of the myocardial substrate, as well as the additive risk created by intense training and competition in susceptible patients with HCM (3). ...in HCM, the most common cause of sudden death in young athletes (1-3), engagement in intense competitive sports is itself an acknowledged modifiable risk factor (1-3). At present, the risk for sudden death in gene-positive-phenotype-negative family members appears to be extremely low and likely no different from the risk in the general population of the same age without heart disease (5,20).\n Cooper, Jr Mayo Clinic None None None None None None None N.A. Mark Estes III Tufts Medical Center None None None None None Medtroniclow *; St. Jude Medicaldagger; Boston Scientificdagger None Mark S. Link Tufts Medical Center None None None None None None None Martin S. Maron Tufts Medical Center None None None None None None None Rick A. Nishimura Mayo Clinic None None None None None None None James E. Udelson Tufts Medical Center Gilead (DSMB member for a clinical trial)low * None None None None None None low * Writing Group Disclosures This table represents the relationships of writing group members that may be perceived as actual or reasonably perceived conflicts of interest as reported on the Disclosure Questionnaire, which all members of the writing group are required to complete and submit.