With regards to diabetes, addressing the first barrier is most critical at the present time. This barrier pertains to the lack of consistent results across populations with regards to the genetic determinants of the disease. Failure to replicate study results may be due to a variety of factors, the most important of which may be that different gene-environment interactions operate different populations to increase risk of developing diabetes. Thus, considerably more epidemiologic research will be needed before we know the actual risk associated with particular genetic variants. This also likely means that we will not be able to apply a ‘one size fits all’ model when it comes to the genetic testing for any of the forms of diabetes. To fulfill the promise of the Human Genome Project, several issues that warrant careful consideration. First, multidisciplinary teams will be required to translate genetic discoveries from the laboratory to the community. This is, perhaps, best exemplified by the development of new initiatives such as the NIH Roadmap in the US. Scientists will no longer be able to work in isolation, without input of individuals from other professions, if they are to maximize the impact of their research in terms of improving health. In particular, issues such as quality assurance, health risks and benefits, and economics need to be addressed. This will require expertise from persons who have typically worked outside the profession of science. Finally, the ethical, legal and social issues associated with widespread availability and use of predictive genetic tests must been addressed. These include confidentiality, discrimination, diversity, informed consent, keeping up with genetic discoveries and uncertainty. Ideally, consideration of such issues will lead to the development of practice guidelines for diabetes, which will hopefully serve as a model for genetic testing for other complex diseases. 11
Acknowledgement: We acknowledge the contribution of Dr Janice S. Dorman, Ph.D., University of Pittsburgh, School of Nursing, 350 Victoria Building, Pittsburgh, PA, USA, to this paper. References 1. Alberti, K.G.M.M., Zimmett, P. Definition, diagnosis and classification of diabetes mellitus and its complications part 1: diagnosis and classification of diabetes mellitus provisional report of a WHO consultation.Diabet Med, 1998. 15: 539-553. 2. Anjos, S., Polychronakos, C. Mechanisms of genetic susceptibility to type 1 diabetes: beyond HLA.Mol Genet Metab, 2004. 81: 187-195. 3. Barroso, I., Luan, J., Middelberg, R.P.S., et al. Candidate gene association study in type 2 diabetes indicates a role for genes involved in B-Cell function as well as insulin action.PLoS Biol, 2003. 1: 41-55. 4. Bennett, S.T., Wilson, A.J., Esposito, L. Insulin VNTR allele-specific effect in type 1 diabetes depends on identity of untransmitted paternal allele.Nat Genet, 1997. 17: 350-352.