Many hereditary disorders in dogs have equivalents in humans and thus attract attention as natural animal models. Breed predisposition to certain diseases often provides promising clues to explore novel hereditary disorders in dogs. Recently, cases of gastrointestinal (GI) polyps in Jack Russell Terriers (JRTs) have increased in Japan. In 21 affected JRTs, polyps were found in either or both the stomach and colorectum, with a predilection for the gastric antrum and rectum. Multiple polyps were found in 13 of 21 examined dogs, including 5 dogs with both gastric and colorectal polyps. Some dogs were found to have GI polyps at an early age, with the youngest case being 2.3 years old. Histopathologically, 43 of 46 GI polyps (93.5%) were diagnosed as adenomas or adenocarcinomas. Immunohistochemical analysis revealed cytoplasmic and nuclear accumulation of β-catenin in the tumor cells. As in the case of human patients with familial adenomatous polyposis, all examined JRTs with GI polyps (n = 21) harbored the identical heterozygous germline APC mutations, represented by a 2-bp substitution (c.[462A>T; 463A>T]). The latter substitution was a non-sense mutation (p.K155X) resulting in a truncated APC protein, thus suggesting a strong association with this cancer-prone disorder. Somatic mutation and loss of the wild-type APC allele were detected in the GI tumors of JRTs, suggesting that biallelic APC inactivation was involved in tumor development. This study demonstrated that despite differences in the disease conditions between human and dog diseases, germline APC mutation confers a predisposition to GI neoplastic polyps in both dogs and humans.

中文翻译：

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犬家族性腺瘤性息肉病：具有种系 APC 突变的杰克罗素梗犬的遗传性胃肠道息肉病。

狗的许多遗传性疾病与人类相同，因此作为天然动物模型受到关注。某些疾病的品种易感性通常为探索狗的新型遗传性疾病提供了有希望的线索。最近，日本杰克罗素梗犬 (JRT) 的胃肠 (GI) 息肉病例有所增加。在 21 个受累的 JRT 中，在胃和结肠直肠中的一个或两个中发现息肉，并且好发于胃窦和直肠。在 21 只接受检查的狗中，有 13 只发现了多处息肉，其中 5 只同时患有胃和结肠直肠息肉。一些狗在很小的时候就被发现患有胃肠道息肉，最小的病例只有 2.3 岁。组织病理学上，46 个 GI 息肉中有 43 个（93.5%）被诊断为腺瘤或腺癌。免疫组织化学分析揭示了 β-连环蛋白在肿瘤细胞中的细胞质和细胞核积累。与患有家族性腺瘤性息肉病的人类患者的情况一样，所有检查的具有 GI 息肉的 JRT（n = 21）都含有相同的杂合种系 APC 突变，由 2-bp 取代（c.[462A>T；463A>T] 表示） ）。后一种替代是无义突变 (p.K155X)，导致 APC 蛋白被截短，因此表明与这种易患癌症的疾病有很强的关联。在 JRT 的胃肠道肿瘤中检测到体细胞突变和野生型 APC 等位基因的丢失，表明双等位基因 APC 失活参与了肿瘤的发展。这项研究表明，尽管人类和狗疾病之间的疾病状况存在差异，