Development of metachronous rectal cancers in a young man with dyskeratosis congenita: a case report

• Published in: Journal of medical case reports Vol. 13; no. 1; p. 117
• Main Authors: Watanabe, Motoko, Yamamoto, Gou, Fujiyoshi, Kenji, Akagi, Yoshito, Kakuta, Miho, Nishimura, Yoji, Akagi, Kiwamu
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 27.04.2019; BioMed Central; BMC
• Subjects: Age; Anemia; Blood pressure; Bone marrow; Cancer; Cancer genetics; Case Report; Case reports; Colorectal cancer; Development and progression; Disease susceptibility; DKC1; Dyskeratosis congenita; Endoscopy; Families & family life; Gastrointestinal diseases; Genes; Genetic aspects; Glycine; Health aspects; Hematology; Hemoglobin; Hepatitis; Immunoglobulins; Missense variant; Mutation; Patients; Proteins; Rectal cancer; RNA; RNA sequencing; Telomerase; Tumors; X-linked recessive; Young men; X-linked recessive; Dyskeratosis congenita; Missense variant; Rectal cancer; DKC1
• DOI: 10.1186/s13256-019-2044-5
• ISSN: 1752-1947

DKC1 (dyskerin pseudouridine synthase 1) is a causative gene for X-linked dyskeratosis congenita. Approximately 8% of patients with dyskeratosis congenita have malignancy, but information about the development of malignancy in patients with dyskeratosis congenita is limited. A young Japanese patient with bone marrow failure developed metachronous rectal adenocarcinomas at the ages of 16 and 18 years. He had no family history of cancer. Microsatellite instability testing with rectal tumor tissue demonstrated low-level microsatellite instability. To clarify whether any cancer susceptibility genes were involved in the development of rectal cancer, RNA sequencing was performed. Cancer-related genes were assessed, and a c.361A>G (p.Ser121Gly) germline variant was detected in DKC1. The same missense variant was previously reported in two patients with dyskeratosis congenita as a pathogenic variant, but those patients did not develop malignancies. Our patient developed rectal cancer at an early age of onset compared with the previously reported typical onset age of patients with dyskeratosis congenita. DKC1 might be involved in predisposition to colorectal cancer in young adulthood; therefore, appropriate surveillance may be considered.