Mosaicism: Implications for Genetic Counseling and Medical Management

Mosaicism describes the presence of two or more populations of cells with different genotypes in one individual that have developed from a single fertilized egg. This article reviews the various clinical presentations of mosaicism associated with hereditary cancer syndromes and the challenges in providing patients and their families with appropriate genetic testing, as well as provides recommendations for cancer presentation and early detection. Management of mosaicism is based on personal and family history, along with genetic testing results.