CCDC112 (coiled-coil domain containing 112), also known as MBC1 (mutated in bladder cancer 1), is a 446 amino acid protein. The gene encoding CCDC112 is located on chromosome 5. Due to alternative splicing events, CCDC112 exists as two isoforms. Chromosome 5 comprises about 6% of human genomic DNA and contains 181 million base pairs encoding around 1,000 genes. It is associated with Cockayne syndrome through the ERCC8 gene and familial adenomatous polyposis through the adenomatous polyposis coli (APC) tumor suppressor gene. Treacher Collins syndrome is also chromosome 5 associated and is caused by insertions or deletions within the TCOF1 gene. Deletion of the p arm of chromosome 5 leads to Cri du chat syndrome. Deletion of 5q or chromosome 5 altogether is common in therapy-related acute myelogenous leukemias and myelodysplastic syndrome.