Scientists at the Heidelberg University Hospital in Germany have found that just one "false" amino acid can limit the strength of heart in zebrafish.
The researcher say that their finding attains significance as the fish have a genetic makeup similar to that of humans, and such defects could be critical for humans as well.
They point out that cardiac insufficiency is not just a disease that results from a heart attack or myocarditis, and that for young people, in particular, there is often an underlying genetic cause (cardiomyopathy).
The genetic variant that suffers from cardiomyopathy is called "Lazy Susan", and got its nickname because of its slow blood flow.
When the researchers examined the muscle protein myosin light chain-1, which is involved in contraction of the heart muscle, they observed the crucial change in the amino acid Serine 195, which was lost through mutation.
The researchers say that this single change is sufficient to severely limit heart function.
Given that about 70 percent of the genes of zebrafish and humans are identical, the researchers say that these results are very important.
The Heidelberg cardiologists are currently planning to search for the same mutation in patients' genes, hoping that their research may lead to new therapies for patients.