Which syndrome is characterized by an increased risk of colorectal cancer without polyps?

Lynch Syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), is characterized by an increased risk of colorectal cancer as well as certain other cancers, including endometrial, ovarian, stomach, and urinary tract cancers, without the presence of polyps. This condition is caused by inherited mutations in mismatch repair (MMR) genes, leading to the accumulation of errors during DNA replication, which increases cancer risk.

Individuals with Lynch Syndrome may have a family history of colorectal and associated cancers, but it is distinctive because individuals do not develop the large number of polyps typical of other syndromes associated with colorectal cancer risk. This direct relationship between MMR mutations and increased cancer risk, particularly for colorectal cancers, makes Lynch Syndrome unique in its presentation and risk factors, solidifying its association with colorectal cancer without the formation of polyps.

The other syndromes listed are related to different patterns of cancer risk or to the presence of polyps, which differentiates them from Lynch Syndrome regarding colorectal cancer predisposition.