Description
Myostatin-related muscle hypertrophy is a rare condition characterized by reduced body fat and increased muscle size. Affected individuals have up to twice the usual amount of muscle mass in their bodies. They also tend to have increased muscle strength. Myostatin-related muscle hypertrophy is not known to cause any medical problems, and affected individuals are intellectually normal.
Frequency
The prevalence of this condition is unknown.
Causes
Variants (also known as mutations) in the MSTN gene cause myostatin-related muscle hypertrophy. The MSTN gene provides instructions for making a protein called myostatin, which is active in muscles used for movement (skeletal muscles) both before and after birth. This protein normally limits muscle growth, ensuring that muscles do not grow too large. Variants that reduce the production of functional myostatin lead to an overgrowth of muscle tissue.
Inheritance
Myostatin-related muscle hypertrophy has a pattern of inheritance known as incomplete autosomal dominance. People with a variant in both copies of the MSTN gene in each cell (homozygotes) have significantly increased muscle mass and strength. People with a variant in one copy of the MSTN gene in each cell (heterozygotes) also have increased muscle bulk, but to a lesser degree.
Other Names for This Condition
Muscle hypertrophy syndrome
Additional Information & Resources
Catalog of Genes and Diseases from OMIM
MYOSTATIN; MSTN
Scientific Articles on PubMed
PubMed
References
Carnac G, Ricaud S, Vernus B, Bonnieu A. Myostatin: biology and clinical relevance. Mini Rev Med Chem. 2006 Jul;6(7):765-70. doi: 10.2174/138955706777698642. Citation on PubMed Schuelke M, Wagner KR, Stolz LE, Hubner C, Riebel T, Komen W, Braun T, Tobin JF, Lee SJ. Myostatin mutation associated with gross muscle hypertrophy in a child. N Engl J Med. 2004 Jun 24;350(26):2682-8. doi: 10.1056/NEJMoa040933. No abstract available. Citation on PubMed