[Advance of the research for disease-responsible genes].

Over the last three decades, many disease-responsible genes have been identified due to advancement of technologies in molecular biology. Methodologies to identify disease-responsible genes have been changed according to the history. Although large subject numbers were needed previously, valuable data derived from only one rare patient have led to identify some disease-responsible genes. Recently launched next-generation sequencers have heralded the new personal genome era. We should know that we may be able to identify some disease-responsible genes by the investigation of only one patient who we meet at the bed side.