Simplified PCR analysis of a mutation in the NHEJ1 gene causing collie eye anomaly in some dog breeds

Abstract

Collie eye anomaly (CEA) is an inherited eye disease affecting development of the choroids and sclera segregating in several, mostly herding breeds of dog. Phenotypic development of the disease varies greatly in the affected animals. Genetic control of its clinical variation is unknown so far. Affected dogs share a 7.8 kb deletion in intron 4 of the NHEJ1 gene. We report here population studies of 379 dogs (Australian Shepherd, Border Collie, Rough Collie, Smooth Collie, Shetland Sheep Dog, and Nova Scotia Duck Tolling Retriever) from breeders in the Czech Republic. A simple PCR method using a Piko<sup>TM</sup> Thermal Cycler and unclotted blood samples was employed for the analysis of the NHEJ1 gene. No isolation of DNA from blood samples before PCR was needed. The method is time-saving and gives excellent results. Frequencies of the disease allele in each breed were calculated (0.045, 0.194, 0.797, 0.367, 0.429 and 0.244, respectively). An improvement of genetic health of the breeds on the basis of allele frequencies is discussed.