PCR-RFLP molecular confirmation of color dilution alopecia in dogs in Brazil.

Color dilution alopecia (CDA) is a dermatopathy observed exclusively in animals having a diluted coat color. In dogs, color dilution occurs as a result of a single-nucleotide variation (SNV)    in the melanophilin gene. We standardized a PCR-restriction-fragment length polymorphism (PCR-RFLP) technique to identify this mutation and determine its frequency in dogs in Brazil. The standardized PCR-RFLP technique could efficiently identify the SNV    in the melanophilin gene, with mutated allele frequencies of 0.1, 0.1, and 0.0875 in Dachshund, Miniature Pinscher, and Yorkshire Terrier breeds, respectively, with no statistical difference among the breeds ( = 0.252). The mutation was identified in 2 homozygous Dachshund dogs with alopecia, confirming the clinical characteristic of CDA. The standardization of a simpler and more accessible molecular technique for recognition of the SNV    in the melanophilin gene allows identification of heterozygous (phenotypically normal) dogs that can be excluded from reproduction, to avoid the birth of dogs with diluted coat color and consequently CDA.