1) Mosaicism results from the mutation in part of somatic cells after the fertilization, only a few cases occur due
to mutation during meiosis. Mosaicism is characterized by genetic or functional difference of two or more cell lines
in one individual from one zygote. 2) Phenotypical variety is high and depends on the proportion of cell lines of
individual clones. 3) Clinical prognosis of mosaic individuum is better in comparison to the full mutation in all cells.
4) The genetic prognosis of reproduction in relatives of the mosaic individuum is without increased recurrent risk,
genetic prognosis of own offspring depends on the moment of mutation occurrence – wheit occurs before day 16 to
20 when gonadal cells are differentiated, it represents high risk of transmission. 5) Diagnosis of mixoploids in some
cases requests investigation of different cells (fibroblasts, lymphocytes). 6) Clinical „signal“ features of the mosaic
are hemihypertrophy, asymmetry, Blaschko lines, pigmentations. 7) Risk of malignant tumor is increased, similarly
to other chromosomal aberrations, chromosomal instability or hamartomatoses. 8) Mosaics of gene mutation have
usually normal mental development and are manifested by external abnormalities only. 9) Incidence of mosaic
phenotypes is high and therefore the diagnosis of mixoploids and gene mosaic is important for the estimation of
clinical as well as genetic prognosis.
mosaicism, cell lines, clinical and genetical prognosis, hemihypertrophy, Blaschko lines, increased
risk for malignancy.