OBJECTIVES: 1. To identify and define any genetic patterns for deaths from myocardial infartion (M.I.) and cerebrovascular accident (CVA) occurring during 1956-76 among members of large Utah pedigrees and estimate heritability. 2. To determine what proportion of MI or CVA deaths in Utah could be wholy or partly attributed to the genetic patterns found, especially among younger deaths of persons in their productive years of life. 3. To determine if possible which specific risk factors are involved in genetic patterns found. SUMMARY OF METHODS: 1. Edit a computer file of Death Certificates for all Utah resident deaths from 1956 to 1976 and update essential missing information (birth date, maiden name) for MI and CVA deaths. 2. Link death certificate file for Utah 1956-76 (137,292 deaths; 41,187 MI, 13,909 CVA) with Utah Computer Pedigree File (400,000 persons in Sept. 1976, over 1 million persons by 1978) using first name, last name, month and year of birth. Estimate heritability from relatedness. 3. Identify, diagram and study pedigrees with excessive clusters of deaths from MI or CVA especially at younger ages. Formulate and test models for gene transmission including the effects of modifiers (age & sex) on phenotypic expression. 4. Analyze pedigrees for a random sample of MI and CVA deaths to determine how frequently the identified genetic patterns occur. 5. Determine if genetic trends in MI or CVA deaths are associated with specific risk factors (i.e., hypertension or hypercholesterolemia) by reviewing medical records of hospitals & physicians for selected apparently genetic related MI & CVA deaths.