For the most part, we can’t control our genes. No amount of hair dye will make me anything other than a natural blonde, no amount of stretching will make me any taller, and no contacts or glasses will make my natural vision any better because that’s what the combination of As, Ts, Cs, and Gs in my DNA codes for. However, new therapies are using DNA – specifically, swapping out bad DNA for functional DNA – to help treat genetic conditions.

Gene therapy, as it’s called, is when a functional copy of a gene is injected into a person who either has a faulty copy of that gene or none at all. The trick is to get that DNA into the right cells in the right tissue: this can either be done ex vivo, where the cells in question are removed and have the DNA injected into them before putting them back in, or in vivo, where the DNA is injected directly into the body.

British medical professionals are set to start a gene therapy trial to treat heart failure by targeting expression of the SERCA gene, which promotes a stronger heartbeat. The gene codes for a protein that tells calcium to go to muscle cells and makes the cells contract, and more expression means more calcium to make the cells contract.

Doctors are using a modified cold virus, consisting only of the SERCA gene and a protein coat, to deliver the DNA to the heart via injection into the carotid artery. Despite the distance it has to travel, the DNA will only target the heart because the SERCA protein only works on the sarcoplasmic reticulum, a cellular structure found only in muscles.

Gene therapy as it stands now isn’t a cure-all, but considering the alternatives are repeated hospital visits or a heart transplant, it’s definitely showing some promise.