he genetic polymorphism of the CSN1S1 locus was investigated in the White Shorthair and Brown Shorthair breeds. These breeds are kept mainly for their good dairy performance. Genetic characterization of the CSN1S1 locus contributes to the knowledge of the genetic structure of these two endangered breeds. The study was performed by means of different polymerase chain reactions (PCR). The analysis showed a prevalence of CSN1S1 F and CSN1S1 A alleles. The frequency of occurrence of E and 01 alleles was very low. No population followed the Hardy-Weinberg equilibrium. Moreover, the test of population differences showed no significant differences between White and Brown Shorthair goats. This genetic peculiarity makes the preservation of the population of both breeds worthwhile.