[Constitutional MMR deficiency: Genetic bases and clinical implications].

[Constitutional MMR deficiency: Genetic bases and clinical implications]. Bull Cancer. 2018 Dec 11;: Authors: Buecher B, Le Mentec M, Doz F, Bourdeaut F, Gauthier-Villars M, Stoppa Lyonnet D, Colas C Abstract Inherited mono-allelic mutation in one of the 4 major MMR genes results in Lynch syndrome which predisposes, in adulthood, mainly to colorectal and endometrial tumors characterized by microsatellite instability (MSI phenotype). Individuals with bi-allelic mutations of one of these genes developed early and multiple malignancies, most often in childhood. This recessively inherited condition is named CMMRD for Constitutional Mismatch Repair Deficiency. The spectrum of tumors is distinct from Lynch syndrome. Malignant brain tumors are at least as frequent as gastrointestinal tumors and in more than a third of cases haematological malignancies were also reported. Patients also displayed clinical features similar of neurofibromatosis type 1, especially café au lait spots. The most commonly involved genes are PMS2 and MSH6 while bi-allelic MLH1 and MSH2 mutations are rare. The digestive tumors of these patients show MSI whereas the brain tumors can be "microsatellite stable". Because of variable clinical presentation and phenotypical overlaps with other cancer syndromes, CMMRD syndrome is frequently unrecognized by clinicians and its incidence is almost certainly underestimated. A better knowledge of clinical criteria and diagnosis m...
Source: Bulletin du Cancer - Category: Cancer & Oncology Authors: Tags: Bull Cancer Source Type: research