1. From the Centre for Cardiovascular Genetics (D.J.B., F.Z., L.J., H.E.M., S.E.H.) and Centre for Clinical Pharmacology (L.J., P.S., A.D.H.), BHF Laboratories at UCL, Royal Free and UCL Medical School, London, UK; Universidad Autónoma de Bucaramanga (N.S.), Bucaramanga, Colombia; Department of Medicine (A.R., G.D.O.L.), University of Glasgow, UK; and Royal Centre for Defence Medicine (M.J.W.), Selly Oak Hospital, Birmingham, UK.