Professor McCarthy is a highly-acclaimed young clinical scientist, whose contributions to the medical sciences in the arena of the genetic basis of diabetes mellitus and the analysis of common multifactorial traits are internationally-recognised and of fundamental importance. He plays a leading role in basic and clinical diabetes research in the UK and internationally. His most important original discoveries are in: (i) Mapping of loci contributing to type 2 diabetes (T2D) susceptibility through linkage analysis (Nature Genetics 1996; American Journal of Human Genetics 2001,2002a,2002b; Human Molecular Genetics 2003; Diabetes 2003, 2004).(ii) Establishing that variants within CAPN10 and KCNJ11 contribute to T2D susceptibility (American Journal of Human Genetics 2001, 2003; Diabetes 2003) (iii) Establishing the role of variation within the INS and IRS1 genes and susceptibility to diverse metabolic diseases/traits (Lancet 1997, Diabetes 2000, 2004a, 2004b, 2004c; Diabetologia 2004) (iv) Understanding the pathophysiology and genetic basis of T2D-related traits including gestational diabetes and polycystic ovary syndrome (Clinical Endocrinology 2000,2002; Journal of Clinical Endocrinology & Metabolism 2002a, 2002b, 2003, 2004a, 2004b) (v)