Genetics of Cardiomyopathy Affairs of the Heart: Living with Inherited Cardiomyopathy February 20, 2016 Kyla Dunn, MS, LCGC Cardiovascular Genetic Counselor Children’s Heart Center, Stanford Children’s Health

Caring for the Whole Family

Genetic Risk What are genes? How do they cause disease? How do these heart conditions run in families? Who else could be at risk?

What is a gene? “GENES” = RECIPES MAKE PROTEINS

99.9% similar Differences between us come from small variations within our genes (that 0.1%) We All Have the Same Set of Genes

Heart Muscle Proteins

Consequences Change in a gene Change in the protein Heart disease

Heart Muscle Walls

How Are These Conditions Inherited? Two copies of every gene One from Mom One from Dad

50%

Relatives At 50% Risk Brothers Sisters Parents Children

Screening Relatives for HCM First visit at age 5 (or 5 years before earliest diagnosis in family) Yearly from ages Every 5 years in adulthood

Uncertainty with Heart Conditions Disease Onset –From birth to late adulthood –Acute (cardiac arrest) or gradual Severity –Variable even within the same family –Minority of cases very severe, majority live “normal lives” Lifelong screening for at-risk individuals No one can predict the future

Disease-causing (pathogenic) change in a gene Limited Success –Hypertrophic Cardiomyopathy: 40-60% –Dilated Cardiomyopathy: 20-40% Genetic Testing

Predictive Genetic Testing Tells you who actually inherited the predisposition Possible when a disease-causing gene variant has been identified in the family

Benefits of Predictive Testing Can protect those who test positive –Cardiac screening recommendations –Lifestyle modifications –Medical therapies –ICD Can “clear” those who test negative –Excuse from clinical cardiology testing, anxiety –Allow to pursue competitive sports

Minimize Risk to Next Generation Preimplantation Genetic Diagnosis (PGD) 8 cell embryo created in the laboratory

Options for At-Risk Relatives Life-long cardiac evaluations Predictive genetic testing, if variant known Do nothing

Caring for the Whole Family