MYH7
Encyclopedia
MYH7 is a gene
encoding a myosin
heavy chain beta (MHC-β) isoform (slow twitch) expressed primarily in the heart.
Changes in the relative abundance of MHC-β and MHC-α (MYH6, the fast isoform of cardiac myosin heavy chain) correlate with the contractile velocity of cardiac muscle
. In early fetal development, MHC-β is predominately expressed in the ventricles, while MHC-α is predominantly expressed in the atria. In healthy adult hearts, MHC-α is predominantly expressed in the atria (>90%), while MHC-β (~50%) is expressed in the atria of failing adult hearts.
In vitro studies have demonstrated that newly formed cardiac myocytes express MHC-β, and after prolonged (1-5 weeks) contractile activity MHC-α becomes detectable.
An allelic variant of this gene is associated with approximately 40% of the cases of Hypertrophic cardiomyopathy
(HCM). This condition is an autosomal-dominant disease, in which a single copy of the variant gene causes enlargement of the left ventricle
of the heart. Disease onset usually occurs later in life, perhaps triggered by changes in thyroid hormone
function and/or physical stress.
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
encoding a myosin
Myosin
Myosins comprise a family of ATP-dependent motor proteins and are best known for their role in muscle contraction and their involvement in a wide range of other eukaryotic motility processes. They are responsible for actin-based motility. The term was originally used to describe a group of similar...
heavy chain beta (MHC-β) isoform (slow twitch) expressed primarily in the heart.
Changes in the relative abundance of MHC-β and MHC-α (MYH6, the fast isoform of cardiac myosin heavy chain) correlate with the contractile velocity of cardiac muscle
Cardiac muscle
Cardiac muscle is a type of involuntary striated muscle found in the walls and histologic foundation of the heart, specifically the myocardium. Cardiac muscle is one of three major types of muscle, the others being skeletal and smooth muscle...
. In early fetal development, MHC-β is predominately expressed in the ventricles, while MHC-α is predominantly expressed in the atria. In healthy adult hearts, MHC-α is predominantly expressed in the atria (>90%), while MHC-β (~50%) is expressed in the atria of failing adult hearts.
In vitro studies have demonstrated that newly formed cardiac myocytes express MHC-β, and after prolonged (1-5 weeks) contractile activity MHC-α becomes detectable.
An allelic variant of this gene is associated with approximately 40% of the cases of Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy is a disease of the myocardium in which a portion of the myocardium is hypertrophied without any obvious cause...
(HCM). This condition is an autosomal-dominant disease, in which a single copy of the variant gene causes enlargement of the left ventricle
Ventricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
of the heart. Disease onset usually occurs later in life, perhaps triggered by changes in thyroid hormone
Thyroid hormone
The thyroid hormones, thyroxine and triiodothyronine , are tyrosine-based hormones produced by the thyroid gland primarily responsible for regulation of metabolism. An important component in the synthesis of thyroid hormones is iodine. The major form of thyroid hormone in the blood is thyroxine ,...
function and/or physical stress.