He trained in rheumatology and epidemiology, but moved into genetic epidemiology in 1992 when he founded the UK Twins Registry, with currently 13,000 twins, which is one of the richest collections of genotypic and phenotypic information on twins worldwide.
He is president of the International Society of Twin Studies and collaborates with over 120 centres worldwide. Its breadth of research has demonstrated the genetic basis of a wide range of common complex traits, many previously thought to be mainly due to ageing and environment. Through GWAS studies his group have found over 400 novel gene loci in over 30 disease areas.
He has published over 700 research articles and is ranked as being in the top 1% of the world’s most published scientists by Reuters.
He is holder of a prestigious European Research Council senior investigator award to study epigenetics as well as many other awards and grants. He is the author of several books, focusing on osteoporosis, genetics, epigenetics and the microbiome, and has been featured widely in the media.