matsumoto was born in saga prefecture, japan, and completed his m.d. in 1986 from kyushu university school of medicine. after residency in obstetrics and gynecology at kyushu university hospital, he worked as an obstetrician and gynecologist for several years. wishing to pursue advanced study in medical genetics, he went to nagasaki university to study as a graduate student under norio niikawa, who discovered kabuki syndrome. he obtained his doctorate in genetics in 1997 from the same institution, before becoming a postdoctoral fellow at the university of chicago. he was appointed professor and chairman of the department of human genetics at yokohama city university school of medicine in 2003.