MedGen

An inherited genetic condition in which members within a family are at an increased risk for the development of benign and/or malignant neoplasms. [from NCI]

Lynch syndrome is characterized by an increased risk for colorectal cancer (CRC) and cancers of the endometrium, ovary, stomach, small bowel, urinary tract, biliary tract, brain (usually glioblastoma), skin (sebaceous adenomas, sebaceous carcinomas, and keratoacanthomas), pancreas, and prostate. Cancer risks and age of onset vary depending on the associated gene. Several other cancer types have been reported to occur in individuals with Lynch syndrome (e.g., breast, sarcomas, adrenocortical carcinoma). However, the data are not sufficient to demonstrate that the risk of developing these cancers is increased in individuals with Lynch syndrome. [from GeneReviews]

Platelet-type bleeding disorder-17 is an autosomal dominant disorder characterized by increased bleeding tendency due to abnormal platelet function. It is a type of 'gray platelet syndrome' because the platelets appear abnormal on light microscopy. Electron microscopy shows decreased or absent alpha-granules within platelets, and bone marrow biopsy shows increased numbers of abnormal megakaryocytes, suggesting a defect in megakaryopoiesis and platelet production. The bleeding severity is variable (summary by Monteferrario et al., 2014). [from OMIM]

Malignant neoplasms occurring in families at a rate greater than that expected by chance and caused by germline mutations in a specific gene. [from NCI]

Lynch syndrome-4 (LYNCH4), or hereditary nonpolyposis colorectal cancer type 4 (HNPCC4), is an autosomal dominant disorder characterized primarily by the development of early-onset colorectal cancer. It is associated with the development of a variety of epithelial tumors that include endometrial cancer, stomach cancer, and ovarian cancer (summary by Thompson et al., 2004). [from OMIM]