In a first attempt a comparative sequencing of all potential OI candidate genes reported in humans, i.e., COL1A1, COL1A2, IFITM5, SERPINF1, CRTAP, LEPRE1, PPIB, SERPINH1, FKBP10, SP7, BMP1, TMEM38B and WNT1, was performed in a cohort comprising the affected OI calf, its parents and 2,612 randomly chosen DNA of healthy Holstein cattle as controls. The gene discussed is COL1A1; the disease is osteogenesis imperfecta.