In the examined Holstein and Montbéliarde dairy cows, nucleotide sequence variations in the form of SNPs kinked to mastitis resistance/susceptibility were detected in the RASGRP1 (410-bp), NFkB (396-bp), CHL1 (547-bp), MARCH3 (455-bp), PDGFD (531-bp), MAST3 (650-bp), EPS15L1 (383-bp), C1QTNF3 (526-bp), CD46 (288-bp), COX18 (511-bp), NEURL1 (476-bp), PPIE (324-bp), and PTX3 (617-bp) genes. The gene discussed is CD46; the disease is mastitis.