1. A method for assessing the presence or risk of type 2 diabetes, cancer, or cardiovascular disease in a subject, comprising the steps of: (a) performing an assay that determines nucleotide sequence of at least a portion of genomic sequence of DACH1 (Dachshund homolog 1) present in a biological sample taken from the subject, and (b) comparing the sequence determined in step (a) with a corresponding standard sequence of DACH1, wherein a variation in the sequence determined in step (a) when compared with the standard sequence indicates that the subject has or is at risk of developing type 2 diabetes, cancer, or cardiovascular disease.