A form of canine cone-rod dystrophy (cord1) was originally associated with a homozygous insertion in RPGRIP1 (RPGRIP1ins/ins) as the primary disease locus while a homozygous deletion in MAP9 (MAP9del/del) was later identified as a modifier associated with the early onset form. The gene discussed is RPGRIP1; the disease is Rod-cone dystrophy.