How reliable are dog DNA tests? Depending on the technology used, they can be very accurate.
The journey of testing your dog’s DNA begins with a swab. After you collect saliva from inside your dog’s cheeks and mail the swab, it arrives at Embark’s CLIA-certified, canine-approved laboratory for processing. The DNA is extracted for analysis under state-of-the-art laboratory conditions. The DNA sample is then run on Embark’s custom SNP microarray.
How accurate are dog DNA tests that use a microarray?
The current state-of-the art canine genetic testing platform is the SNP microarray. SNP stands for single nucleotide polymorphism, an informative type of genetic mutation. Unlike single mutation tests, which test DNA at a single genomic region, microarrays use probes to sample regions across the entire canine genome. Not all dog DNA companies use SNP microarrays, which means older technologies or single mutation tests can’t search for as many markers, or provide as many results from a single test. By using a microarray you can not only test for multiple genetic health risks at once, but also test for breed ancestry, traits, and genetic diversity.
Laboratory guidelines and quality control
Embark ensures quality control of their tests by using an ISO and Clinical Laboratory Improvement Amendments (CLIA)-accredited laboratory for processing. Embark ensures their own quality control since the FDA does not currently regulate genetic testing in dogs. Three federal agencies comprise the CLIA: The Food and Drug Administration (FDA), Center for Medicaid Services (CMS), and the Center for Disease Control (CDC). The CLIA certification is the same used by DNA labs that process human samples.
Using automation and redundancy, every sample is barcoded and handled by robots so the samples are never touched by humans, thus reducing the risk of contamination, or mixing up samples. Before the samples even get to the lab, many breeders and registries also use veterinarian verification to add an extra layer of documentation to the sample.
How accurate are dog DNA tests to determine genetic health risk?
Individual probes on the Embark SNP microarray are based on Illumina’s CanineHD SNP array. The microarray is not a proprietary technology, as many human and canine DNA companies use this platform. However, Embark has customized its probes for more results such as 270+ genetic health risks, 55 traits, and genetic diversity. Each genetic health condition is tested using multiple probes. This redundancy gives an extremely high genotyping accuracy with >99% accuracy for mutation tests and most linkage-based tests.
How accurate are dog DNA tests with linkage tests?
Most of the genetic health risks are discovered through variant tests where probes determine the genotype of the disease-causing mutation. Sometimes, it’s not possible to identify the causative variant for a genetic health risk. However, scientists may have found sections of DNA that can be inherited next to the unknown variant. They perform a linkage disequilibrium or LD test, where they are looking for the mutation of interest by looking at the genetic variation nearby the unknown gene. Embark notes when they are reporting out an LD test, such as POMC or IVDD, for full transparency.
How accurate are dog DNA tests to determine breed ancestry?
Dog DNA tests can also determine breed ancestry. Dog breeds are a unique genetic model when determining ancestry since they are a result of selective breeding by humans over the centuries. This selective breeding created haplotypes, or patterns of DNA sequences. Each dog’s haplotype is a result of the genetic makeup of the parents passed on to their offspring that appear in the canine genome. Each breed has its own group of haplotypes. Haplotypes have been mapped by canine geneticists and shared through peer-reviewed papers and public databases. Embark has built its own haplotype database by adding breed reference panels of 350+ breeds to ensure the accuracy of the breed ancestry as reported.
