Comparative Genomic Analysis of Multiple Mammary Tumors from a Single Dog: Whole-Genome Sequencing Study

Background Next-generation sequencing (NGS) is recognized as a powerful tool for identifying genomic variants in individuals and is widely utilized in oncology research. Results In this study, whole-genome sequencing (WGS) analysis on seven different types of mammary gland tumors (MGTs) and a blood sample from a single dog was performed. WGS achieved an average sequencing depth of 34.5X with 94.9% of the genome covered by at least 20X. Identified mutations causing amino acid substitutions were found to affect the following high-risk genes: HECTD4 (malignant tumors), NIPBL (epithelial-derived malignant tumors), and BRCA2 , TP53 (human ortholog genes associated with breast cancer). Conclusions As this was a single case, the genetic information for each sample was completely identical, and it was possible to identify somatic variations in each histopathological type. This study is expected to provide an innovative fundamental basis for the ongoing advancements in precision medicine in both human and veterinary medicine.