This research has been funded by the British Heart Foundation.
SCD is a major cause of mortality worldwide, and when it occurs in young children and adolescents is particularly devastating. Daniel Yorath, son of former Wales soccer team manager, Terry, is amongst those to have suffered sudden cardiac death.
Recent advances have shown that the genetic mutations in the heart's calcium release channels (known as ryanodine receptors) destroy the ability of the channels to work properly following stress or exercise. These channels released too much calcium, possibly explaining how in affected young people, the normal heart signalling is severely disrupted and could lead to fatally high heart rates (tachycardia) and a loss of co-ordinated heart rhythm (arrhythmia).
Despite these advances, pinpointing the changes that occur within the mutant channel molecules that cause the increase in calcium release remained elusive. These new insights show that normal channels open and close in a tightly regulated fashion, but that mutations make the activated channels 'jittery' and prevent them from closing properly.
The research is published online in Circulation Research 8 December 2005 and in print 6 January 2006.
Dr Christopher George, who led the research explained:
"This is crucial new evidence that mutation-linked abnormalities in cardiac calcium release may arise from defects in the channel structure. Although there is a long way to go, this finding gives us vital clues that the precise stabilisation of these channels may represent the best way to prevent this catastrophic disease in people containing this faulty gene."
Work is already underway to develop a new therapeutic approach which is hoped will eventually restore proper channel closure and may help prevent SCD in susceptible individuals.