WGS for Pets: When Is Whole-Genome Sequencing Worth More Than an Array?

Key Takeaways

• WGS (Whole Genome Sequencing) reads the entire genome's DNA sequence.
• It gives the most detailed data, but is costly, slow, and complex to interpret.
• For routine breed and disease testing, Microarray is still more cost-effective and on-target.
• WGS suits research or cases hunting for novel variants the array doesn't yet cover.

Many hear "decode the whole genome" and assume it must be the best. But in practice, choosing a pet DNA technology depends on "fitness for the job." This article explains what WGS is, when it's worth it, and when Microarray answers better.

What Is WGS?

Whole Genome Sequencing reads the DNA sequence base by base across the entire genome, start to finish. In theory it gives the most detailed data because it covers every position, including ones no one has known before. The power of WGS is visible in work that sequenced over 700 dogs and wild canids, cataloging more than 91 million genetic variants (Plassais et al., Nature Communications, 2019). It sounds perfect, but this level of detail comes with costs to consider.

The Price of Detail

WGS has several important practical limitations. First, high cost — several times that of an array. Second, it takes longer, both to read and to process. Third, enormous data, requiring heavy storage and computing power. And most importantly, it yields many variants of "uncertain significance" (VUS) that can't be interpreted and may create more confusion than benefit.

Why Microarray Still Answers Better for Routine Work

For breed testing and screening common genetic diseases, the important positions are already discovered and validated, and Microarray tests them completely, accurately, and far more cost-effectively. In fact, research confirms a standard-density SNP array is "sufficient" for detecting genetic associations within a breed, with WGS adding extra power mainly for across-breed or mixed-breed studies (Friedenberg et al., PLoS Genetics, 2019). Owners get the answers they want — breed, disease risk, and traits — without paying for whole-genome sequencing that's mostly unused data. This connects with Microarray vs Sequencing.

So When Is WGS Worth It?

WGS has real value in some situations — research that must discover novel variants the array doesn't cover, studying rare diseases of unknown genetic cause, or building reference databases for new breeds, as in large-scale studies that used WGS to find genes behind physical traits and genomic regions under selection (Plassais et al., Nature Communications, 2019). In these cases, WGS's coverage is essential. But for everyday pet owners wanting to know their pet, the array is the smarter choice. This connects with what a pet DNA test can tell you.

Author's Final Note

"Most detailed" doesn't always mean "most fitting." Choosing the technology that matches the purpose is the heart of good DNA testing. For real-life pet testing, Microarray offers the most lovely balance. If you're interested in DNA testing for your pet, feel free to consult the Geneus Pet team.

References

1. Plassais J, et al. Whole genome sequencing of canids reveals genomic regions under selection and variants influencing morphology. Nature Communications. 2019;10:1489. Nature
2. Imputation of canine genotype array data using 365 whole-genome sequences improves power of genome-wide association studies. PLoS Genetics. 2019. NCBI PMC
3. Vaysse A, et al. Identification of Genomic Regions Associated with Phenotypic Variation between Dog Breeds using Selection Mapping. PLoS Genetics. 2011;7(10):e1002316. NCBI PMC
4. A Genome-Wide Detection of Copy Number Variations Using SNP Genotyping Arrays in Dogs. Genes. 2019. NCBI PMC