Cloning of responsible genes for hereditary neurological diseases has been one of the most important fields in disease genome research since early days. To date, over two hundred genes for degenerative diseases have been identified. The accomplishment of the Human Genome Project and the development of DNA chip technology enabled man to conduct genome-wide association study(GWAS) of large scale sample sets, opening the way to elucidate genetic factors of sporadic diseases. Several results have been reported, including GWAS for amyotrophic lateral sclerosis and multiple sclerosis. Now new sequencing technology is emerging, which makes personal genome resequencing possible. Deep resequencing or personal genome would change revolutionarily the paradigm of genome research and medicine.