Biomedical researchers studying gene function should consider the impact of variation, even if genetics is not the primary objective of an investigation. Information on genetic variation can provide a valuable insight into the functional range and critical regions of a gene, protein or regulatory element. Genetic variants may be diverse in nature, ranging from single nucleotide variants, tandem repeats, small insertions or deletions to large copy number variants. Until recently, information on genetic variation was quite limited, but now a range of large scale surveys of variation have made plentiful data on common variation and a picture is beginning to emerge from the driving forces in human evolution and population diversification. Next-generation sequencing technologies are moving knowledge into a new phase focused on the individual genome and complete disclosure of individual variation, including the rarest of variants. The consequences of these advances in medicine are unresolved, but it is clear that biomedical researchers cannot afford to ignore this information. This review presents a broad overview of the in silico methods that will allow a researcher to quickly review known variation in a gene of interest, providing some pointers for further investigation.