A "once-in-a-generation" jab that could "cure" genetic heart conditions that cause sudden death is just a few years away, scientists say.

An international team of researchers is developing the first cures for inherited heart muscle diseases by rewriting DNA with the aim of editing or silencing faulty genes.

They have been awarded £30m by the British Heart Foundation (BHF) to fund their research.

The hope is that within just a few years a "cure" injection can be delivered to patients as a jab in the arm, and could be used to prevent illness in family members who carry the same faulty gene.

Inherited heart muscle conditions are driven by different abnormalities in the heart but can cause sudden death or progressive heart failure.

Every week in the UK, 12 people under the age of 35 die of an undiagnosed heart condition, very often caused by an inherited heart muscle disease, also known as genetic cardiomyopathy.

All those with genetic cardiomyopathies have a 50-50 risk of passing faulty genes on to each of their children and, often, several members of the same family develop heart failure, need a heart transplant, or die at a young age.

Professor Hugh Watkins, from the University of Oxford and lead investigator of the CureHeart project, said cardiomyopathies are "really common" and affect one person in every 250.

"There will be one or two in every school," he told a briefing. "Every GP surgery will have several patients with these conditions, but there's quite a range of severity."

He said not all patients would require the new therapy being proposed, but "a very large number" would benefit.

He added: "This is our once-in-generation opportunity to relieve families of the constant worry of sudden death, heart failure, and the potential need for a heart transplant.

"After 30 years of research, we have discovered many of the genes and specific genetic faults responsible for different cardiomyopathies, and how they work. We believe that we will have a gene therapy ready to start testing in clinical trials in the next five years."