A8V is point mutation on

Troponin C Troponin C is a protein which is part of the troponin complex. It contains four calcium-binding EF hands, although different isoforms may have fewer than four functional calcium-binding subdomains. It is a component of thin filaments, along wi ...

(cTNC) that leads to a

hypertrophic cardiomyopathy Hypertrophic cardiomyopathy (HCM, or HOCM when obstructive) is a condition in which the heart becomes thickened without an obvious cause. The parts of the heart most commonly affected are the interventricular septum and the ventricles. This r ...

. The coordinated cardiac muscle contraction is regulated by the troponin complex on thin filament (troponin C which is calcium binding,

troponin T Troponin T (shortened TnT or TropT) is a part of the troponin complex, which are proteins integral to the contraction of skeletal and heart muscles. They are expressed in skeletal and cardiac myocytes. Troponin T binds to tropomyosin and helps ...

that plays the role with

tropomyosin Tropomyosin is a two-stranded alpha-helical, coiled coil protein found in actin-based cytoskeletons. Tropomyosin and the actin skeleton All organisms contain organelles that provide physical integrity to their cells. These type of organelles a ...

, and

troponin I Troponin I is a cardiac and skeletal muscle protein family. It is a part of the troponin protein complex, where it binds to actin in thin myofilaments to hold the actin-tropomyosin complex in place. Troponin I prevents myosin from binding to ac ...

which has an inhibitory action annulating the S1 ATPase activity in the presence of tropomyosin and troponin and absence of Ca²⁺). This mutation is determined by the change of Alanine to Valine at nucleotide 23 from C to T. Patients with this type of mutation shows thickness on the left ventricle wall of around 18 mm, compared to the normal this thickness would be 12 mm.{{Cite journal, last1=Pinto, first1=Jose Renato, last2=Parvatiyar, first2=Michelle S., last3=Jones, first3=Michelle A., last4=Liang, first4=Jingsheng, last5=Ackerman, first5=Michael J., last6=Potter, first6=James D., date=2009-07-10, title=A Functional and Structural Study of Troponin C Mutations Related to Hypertrophic Cardiomyopathy, journal=Journal of Biological Chemistry, volume=284, issue=28, pages=19090–19100, doi=10.1074/jbc.M109.007021, issn=0021-9258, pmc=2707221, pmid=19439414, doi-access=free Also, A8V affects the Ca²⁺ binding affinity compared to normal genotype and increased sensitivity on force development.

References

Mutation Troponin