C282Y mutation and type 2 diabetesBMJ 2000; 321 doi: https://doi.org/10.1136/bmj.321.7271.1288/b (Published 18 November 2000) Cite this as: BMJ 2000;321:1288
Study was much too small for inferences to be drawn
- David Curtis (Dcurtis@hgmp.mrc.ac.uk), consultant psychiatrist
- East London and City Mental Health NHS Trust, Department of Adult Psychiatry, Royal London Hospital, London E1 1BB
- Research Institute of Public Health, University of Kuopio, Box 1627, 70211 Kuopio, Finland
- Department of Medicine, Helsinki University Hospital, 00290 Helsinki, Finland
EDITOR—Inconclusive genetic studies should not be published in the BMJ. Once again the journal has published a genetic association study based on a tiny sample of cases and producing scarcely significant results.1 It has allowed the authors to claim that they may have identified an important risk factor for a common and serious disease, on the basis of only the flimsiest of evidence.
The authors report a study that, owing to its prospective design, was of just 27 subjects who developed diabetes along with 481 others who remained unaffected. They identified the C282Y mutation in the haemochromatosis gene as a predictor for developing diabetes (P=0.047). Given the very small numbers in the study (with only five subjects carrying the mutation becoming affected), it …