[1] Univ Edinburgh, Rheumat Dis Unit, Edinburgh, Midlothian, Scotland
[2] Univ Auckland, Dept Med, Auckland, New Zealand
[3] Univ Melbourne, Dept Clin & Biomed Sci, Melbourne, Vic, Australia
[4] Sir Charles Gairdner Hosp, Dept Endocrinol, Perth, WA 6000, Australia
[5] Royal Liverpool Univ Hosp, Dept Clin Chem, Liverpool, Merseyside, England
[6] MRC, Human Genet Unit, Inst Genet & Mol Med, Edinburgh, Midlothian, Scotland
[7] Univ Sydney, Dept Med, Sydney, NSW 2006, Australia