What's hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy (HCM) refers to the unexplained thickening of the left ventricle wall of the heart. This is known as left ventricular hypertrophy (LVH). LVH occurs in a non-dilated ventricle in the absence of other systemic disease that can cause thickening of the heart muscle. There is a wide range of symptoms in HCM including: no symptoms, chest pain, shortness of breath, heart palpitations, progressive heart failure, and sudden cardiac death (SCD). These symptoms can vary from individual to individual and even affected people in the same family can have different symptoms. Sometimes, the first symptom of HCM is sudden cardiac death.
HCM is caused by changes in several genes that are all involved in making a part of the heart muscle called a sarcomere. It is inherited in an autosomal dominant manner meaning that an affected person only needs to have one change in one gene to be at risk to develop symptoms of HCM. HCM also has variable expressivity and reduced/incomplete penetrance. Variable expressivity means that different people, even within the same family, can have different symptoms; symptoms aren't always the same in everyone who has HCM. Reduced/incomplete penetrance means that a person can have a gene change for HCM but never develop symptoms.
SOURCE: Emory University - Department of Human Genetics in collaboration with ThinkGenetic • https://www.thinkgenetic.com/diseases/hypertrophic-cardiomyopathy-109928/overview/66519 • DATE UPDATED: 2019-11-18
Maron, et. al. Hypertrophic Cardiomyopathy Present and Future, with translation into contemporary cardiovascular medicine. Journal of the American College of Cardiomyopathy. vol. 64, no. 1; 2014.
Cirino, A.L., Ho, C. (2019). GeneReviews. Hypertrophic Cardiomyopathy Overview. Retrieved September 9, 2019 from https://www.ncbi.nlm.nih.gov/books/NBK1768/