MedGen

Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased ventricular wall thickness or mass in the absence of loading conditions (hypertension, valve disease) sufficient to cause the observed abnormality. [from HPO]

Any dilated cardiomyopathy in which the cause of the disease is a mutation in the MYPN gene. [from MONDO]

A disorder that affects the muscle tissue of the heart. Representative examples include myocardial infarction, myocarditis, and cardiomyopathy. [from NCI]

While most people with familial hypertrophic cardiomyopathy are symptom-free or have only mild symptoms, this condition can have serious consequences. It can cause abnormal heart rhythms (arrhythmias) that may be life threatening. People with familial hypertrophic cardiomyopathy have an increased risk of sudden death, even if they have no other symptoms of the condition. A small number of affected individuals develop potentially fatal heart failure, which may require heart transplantation.

The symptoms of familial hypertrophic cardiomyopathy are variable, even within the same family. Many affected individuals have no symptoms. Other people with familial hypertrophic cardiomyopathy may experience chest pain; shortness of breath, especially with physical exertion; a sensation of fluttering or pounding in the chest (palpitations); lightheadedness; dizziness; and fainting.

Nonfamilial hypertrophic cardiomyopathy tends to be milder. This form typically begins later in life than familial hypertrophic cardiomyopathy, and affected individuals have a lower risk of serious cardiac events and sudden death than people with the familial form.

In familial hypertrophic cardiomyopathy, cardiac thickening usually occurs in the interventricular septum, which is the muscular wall that separates the lower left chamber of the heart (the left ventricle) from the lower right chamber (the right ventricle). In some people, thickening of the interventricular septum impedes the flow of oxygen-rich blood from the heart, which may lead to an abnormal heart sound during a heartbeat (heart murmur) and other signs and symptoms of the condition. Other affected individuals do not have physical obstruction of blood flow, but the pumping of blood is less efficient, which can also lead to symptoms of the condition. Familial hypertrophic cardiomyopathy often begins in adolescence or young adulthood, although it can develop at any time throughout life.

Hypertrophic cardiomyopathy is a heart condition characterized by thickening (hypertrophy) of the heart (cardiac) muscle. When multiple members of a family have the condition, it is known as familial hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy also occurs in people with no family history; these cases are considered nonfamilial hypertrophic cardiomyopathy.  [from MedlinePlus Genetics]

Familial hypertrophic cardiomyopathy-3 (CMH3) is an autosomal dominant disorder characterized by increased myocardial mass with myocyte and myofibrillar disarray (Thierfelder et al., 1994). For a general phenotypic description and a discussion of genetic heterogeneity of hypertrophic cardiomyopathy, see CMH1 (192600). [from OMIM]

An autosomal dominant subtype of dilated cardiomyopathy caused by mutation(s) in the LDB3 gene, encoding LIM domain-binding protein 3. [from NCI]

A myocardial disorder in which the heart muscle is structurally and functionally abnormal, in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to cause the observed myocardial abnormality. [from HPO]

Hereditary ventricular hypertrophy (CMH, HCM, ASH, or IHSS) in early stages produces a presystolic gallop due to an atrial heart sound, and EKG changes of ventricular hypertrophy. Progressive ventricular outflow obstruction may cause palpitation associated with arrhythmia, congestive heart failure, and sudden death. Seidman (2000) reviewed studies of hypertrophic cardiomyopathy in man and mouse. Reviews Walsh et al. (2022) reviewed hypertrophic cardiomyopathy phenotypes associated with variation in genes encoding nonsarcomeric proteins. The authors suggested that these genes likely contribute to polygenic risk scores derived from genomewide association studies that could be used to improve risk assessment in patients and family members, and noted that the diverse functions of the proteins highlight novel disease pathways and therapeutic targets for cardiomyopathies. Genetic Heterogeneity of Hypertrophic Cardiomyopathy Additional forms of hypertrophic cardiomyopathy include CMH2 (115195), caused by mutation in the TNNT2 gene (191045) on chromosome 1q32; CMH3 (115196), caused by mutation in the TPM1 gene (191010) on chromosome 15q22; CMH4 (115197), caused by mutation in the MYBPC3 gene (600958) on chromosome 11p11; CMH6 (600858), caused by mutation in the PRKAG2 gene (602743) on chromosome 7q36; CMH7 (613690), caused by mutation in the TNNI3 gene (191044) on chromosome 19q13; CMH8 (608751), caused by mutation in the MYL3 gene (160790) on chromosome 3p21; CMH9 (613765), caused by mutation in the TTN gene (188840) on chromosome 2q31; CMH10 (608758), caused by mutation in the MYL2 gene (160781) on chromosome 12q24; CMH11 (612098), caused by mutation in the ACTC1 gene (102540) on chromosome 15q14; CMH12 (612124), caused by mutation in the CSRP3 gene (600824) on chromosome 11p15; CMH13 (613243), caused by mutation in the TNNC1 gene (191040) on chromosome 3p21; CMH14 (613251), caused by mutation in the MYH6 gene (160710) on chromosome 14q12; CMH15 (613255), caused by mutation in the VCL gene (193065) on chromosome 10q22; CMH16 (613838), caused by mutation in the MYOZ2 gene (605602) on chromosome 4q26; CMH17 (613873), caused by mutation in the JPH2 gene (605267) on chromosome 20q12; CMH18 (613874), caused by mutation in the PLN gene (172405) on chromosome 6q22; CMH20 (613876), caused by mutation in the NEXN gene (613121) on chromosome 1p31; CMH21 (614676), mapped to chromosome 7p12.1-q21; CMH22 (see 615248), caused by mutation in the MYPN gene (608517) on chromosome 10q21; CMH23 (see 612158), caused by mutation in the ACTN2 gene (102573) on chromosome 1q43; CMH24 (see 601493), caused by mutation in the LDB3 gene (605906) on chromosome 10q23; CMH25 (607487), caused by mutation in the TCAP gene (604488) on chromosome 17q12; CMH26 (617047), caused by mutation in the FLNC gene (102565) on chromosome 7q32; CMH27 (618052), caused by mutation in the ALPK3 gene (617608) on chromosome 15q25; CMH28 (619402), caused by mutation in the FHOD3 gene (609691) on chromosome 18q12; and CMH29 (620236), caused by mutation in the KLHL24 gene (611295) on chromosome 3q27. The CMH5 designation was initially assigned to a CMH family showing genetic heterogeneity. Subsequently, affected individuals were found to carry mutations in the MYH7 (CMH1) and/or MYBPC3 (CMH4) genes. Mutations in the CALR3 gene (611414), previously suggested to cause a form of CMH (Chiu et al., 2007) designated CMH19, were convincingly shown not to be a monogenic cause of cardiomyopathy by Verhagen et al. (2018); see 611414.0001. Hypertrophic cardiomyopathy has also been associated with mutation in the gene encoding cardiac myosin light-peptide kinase (MYLK2; see 606566.0001), which resides on chromosome 20q13.3; the gene encoding caveolin-3 (CAV3; see 601253.0013), which maps to chromosome 3p25; and with mutations in genes encoding mitochondrial tRNAs: see mitochondrial tRNA-glycine (MTTG; 590035) and mitochondrial tRNA-isoleucine (MTTI; 590045). [from OMIM]

A fixed form of obstruction to blood flow across the left-ventricular outflow tract related to stenosis (narrowing) below the level of the aortic valve. [from HPO]

Disease of the heart muscle associated with electrical or mechanical dysfunction, in which the heart is the sole or predominantly involved organ. [from SNOMEDCT_US]

Any heart disorder characterized by a defect in valve structure or function. [from NCI]

The presence of a stenosis (narrowing) of the aortic valve. [from HPO]

Aortic valve disease-3 (AOVD3) is characterized by aortic stenosis and/or bicuspid aortic valve (BAV), associated in some patients with aneurysm of the aortic root and/or ascending aorta. Atrial septal defect (ASD) has also been observed in some individuals (Gould et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of aortic valve disease, see AOVD1 (109730). [from OMIM]