Mark has four siblings. His three brothers are all professional musicians. His oldest brother John is a bass player who lives in Los Angeles and performs around the world with guitarist Scott Henderson. His brother Paul is a singer/songwriter who lives in Ontario, Canada. Paul was a member of the Toronto based new-wave group Blue Peter in the 1980's and is currently pursuing a solo career. His youngest brother Andy is a professional singer/songwriter/guitarist who lives in Portugal. Mark's sister Lesley is a former top model at Ford who has appeared on the cover of Vogue; she now works as a stage manager in Toronto.