First-decade patient with colorectal cancer carrying both germline and somatic mutations in APC gene

Background: Colorectal carcinoma (CRC) is one of the most common causes of cancer-related deaths. The mean age of patients with CRC ranges from 49 to 60 years. Pediatric CRC is unusual, which often escapes early diagnosis because of a lack of awareness of its occurrence in children. The association between the mutation of APC and the occurrence of CRC in the first decade of life remains unknown. Case presentation: We report a 10-year-old child with CRC; he was diagnosed with stage IIIB advanced transverse colon cancer without distal metastases. We detected a heterozygous germline mutation at c.5465 T > A in both blood and tissue samples and a heterozygous somatic mutation at c. 7397C > T in the tissue sample. Both of these mutations can cause CRC tumorigenesis in the first decade of life. Conclusions: The rare genetic features of this 10-year-old patient might be the predisposing cause of pediatric CRC. Therefore, screening patients with early-onset CRC through clinical and genetic characterizations is suggested.