A novel multiplex polymerase chain reaction assay for the genotypic survey of the non-homologous end-joining factor 1 gene associated with Collie eye anomaly in Thailand.

BACKGROUND AND AIM

Collie eye anomaly (CEA) is a hereditary and congenital ocular disorder, which affects several dog breeds, including Collies, Collie-related breeds, and other purebreds. An intronic deletion of 7799-bp in the non-homologous end-joining factor 1 () gene has been identified as the genetic defect causing CEA. This study aimed to investigate the prevalence of CEA based on genotyping assay in Thailand.

MATERIALS AND METHODS

We clarified the prevalence of CEA in 224 dogs from five purebred dog breeds using a novel multiplex polymerase chain reaction (PCR)-based technique and confirmed the genotypic status with direct DNA sequencing.

RESULTS

The highest frequency of the mutated allele was 83.3% for Rough Collies, followed by 7.8% for Border Collies, 5.1% for Australian Shepherds, and 2.8% for Shetland Sheepdogs. The heterozygous mutated genotype detected for Rough Collies, Border Collies, Australian Shepherds, and Shetland Sheepdogs was 33.3%, 15.6%, 10.3%, and 3.3%, respectively. The homozygous mutated genotype was detected only in Rough Collies and Shetland Sheepdogs, accounting for 66.7% and 1.1%, respectively. Thai Ridgeback Dogs were not affected by this mutation.

CONCLUSION

This study describes, for the 1 time, the genotypic survey of the gene associated with CEA in dogs in Thailand. In addition, we successfully developed a new multiplex PCR assay with high accuracy, reproducibility, and cost-efficiency and validated its usefulness for determining genotypes.