[1] Harrogate Dist Hosp, Harrogate HG2 7SX, England
[2] Leeds Childrens Hosp NHS Trust, Leeds, W Yorkshire, England
[3] Cambridge Univ Hosp, Wellcome Trust, Cambridge, England
[4] Addenbrookes Hosp, Dept Clin Biochem, Cambridge, England
[5] Royal Surrey Cty Hosp, SAS Peptides Hormone Sect, Surrey, England
[6] Leeds Teaching Hosp NHS Trust, Blood Sci Dept, Leeds, W Yorkshire, England