12 Henderson T, Shepheard J, Sundararajan V. Quality of diagnosis and procedure coding in ICD-10 administrative data. Med Care 2006; 44: 1011–19. 13 Australian Institute of Health and Welfare. Health Care Usage and Costs. A Comparison of Veterans and war Widows and Widowers within the Rest of the Community. Canberra (ACT): AIHW; 2002. AIHW Cat. no. PHE 42. 14 Somerfield JS, Barber PA, Anderson NE, Kumar A, Spriggs D, Charleston A et al. Not all patients with atrial fibrillation- associated ischemic stroke can be started on anticoagulant therapy. Stroke 2006; 37: 1217–20. Maturity-onset diabetes of the young type 5 in a family with diabetes and mild kidney disease diagnosed by whole exome sequencing J. M. Wentworth, 1,2,4 V. Lukic, 1 M. Bahlo, 1,4,5 M. Finlay, 3 C. Nguyen, 6,7 G. Morahan 6,7 and L. C. Harrison 1,4 1 Molecular Medicine Division, The Walter and Eliza Hall Institute of Medical Research, Departments of 2 Diabetes and Endocrinology and 3 Anatomical Pathology, Royal Melbourne Hospital, Departments of 4 Medical Biology and 5 Mathematics and Statistics, The University of Melbourne, Melbourne, Victoria, 6 Centre for Diabetes Research, The Western Australian Institute for Medical Research, and 7 Centre for Medical Research, University of Western Australia, Perth, Western Australia, Australia Key words MODY5, HNF1B, glomerulocystic kidney disease, maturity-onset diabetes of the young, whole exome sequencing. Correspondence John M. Wentworth, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Vic. 3052, Australia. Email: wentworth@wehi.edu.au Received 7 April 2014; accepted 10 June 2014. doi:10.1111/imj.12584 Abstract Exome sequencing is being increasingly used to identify disease-associated gene muta- tions. We used whole exome sequencing to determine the genetic basis of a syndrome of diabetes and renal disease affecting a mother and her son. We identified a mutation in the hepatocyte nuclear factor 1-b (HNF1B) gene that encoded a methionine to valine amino acid change (M160V) in the HNF1B protein. This leads us to the previously unappreciated diagnosis of maturity-onset diabetes of the young type 5 and provided a basis for genetic counselling of other family members. In 1967, the mother, aged 16 years and not overweight, presented with thirst and polyuria following a bout of tonsillitis. Hyperglycaemia was confirmed and she com- menced insulin therapy for presumed type 1 diabetes. At the same time, she was noted to have moderate renal impairment (creatinine 0.17 μM), normal urine micros- copy and <1 g/24 h proteinuria. Her pregnancy at age 22 years was complicated by hypertension and further deterioration of renal function. Her male child was deliv- ered at 33 weeks gestation weighing 1260 g, 40 g below the third centile for age. In 1975, she had a renal biopsy that was reported to show minor, non-specific features that included focal tubular atrophy, interstitial fibrosis and mesangial proliferation. A second pregnancy to the same father delivered another son, of normal birth weight (2130 g), at 33 weeks gestation. Her renal func- tion then progressively deteriorated, and she required dialysis at age 50 years followed by combined kidney/ pancreas transplantation at age 53 years. At the time of her transplant, her fasting C-peptide level was below the Funding: This work was funded by programme (1037321) and infrastructure grants from the National Health and Medical Research Council of Australia (NHMRC), a Victorian State Gov- ernment Operational Infrastructure Support Grant, the Diabetes Australia Research Trust, and the Royal Australian College of Physicians Research Foundation. Conflict of interest: None. Brief Communications © 2014 The Authors Internal Medicine Journal © 2014 Royal Australasian College of Physicians 1137