On Oct. 3, in a prelude to the 50th meeting of the American Society of Human Genetics in Philadelphia, several hundred geneticists attended a one-day international conference on the genetics of complex diseases. Organized by the National Disease Research Interchange, a Philadelphia-based nonprofit coordinating organization, the agenda included sessions on the genetics of thyroid disease, type I diabetes, and autism. The first session, "Defining the Genetics of Complex Disease," chaired by National Human Genome Research Institute (NHGRI) director Francis Collins, sought to identify and discuss several factors that complicate investigations into the genetic underpinnings of disease. Collins outlined five topics: estimating heritability, understanding phenotypic information, study design, the difficulty of replicating findings on the genetics of disease, and disease-mapping usefulness of single nucleotide polymorphisms (SNPs). Some general themes of the discussion included:
* Disease phenotypes have been under-appreciated by geneticists; ideally investigators should initially study phenotypes without knowing genotypes to ...