Mosaicism in Tuberous Sclerosis as a Potential Cause of the Failure of Molecular Diagnosis

Abstract
Mosaicism is the phenomenon in which a fraction of, rather than all, germ-line and somatic cells contain a mutation or chromosomal abnormality. It occurs in all genetic disorders in which spontaneous mutations occur and has important clinical consequences for the assessment of patients with localized expression of multisystem disorders, for genetic counseling, and for molecular diagnostic testing.1,2