biostudies-literatureThorpe JNICHD NIH HHSNIMH NIH HHS487-510https://www.ebi.ac.uk/biostudies/studies/S-EPMC8483770biostudies-literatureUnknown54Mosaicism refers to the occurrence of two or more genomes in an individual derived from a single zygote. Germline mosaicism is a mutation that is limited to the gonads and can be transmitted to offspring. Somatic mosaicism is a postzygotic mutation that occurs in the soma, and it may occur at any developmental stage or in adult tissues. Mosaic variation may be classified in six ways: (<i>a</i>) germline or somatic origin, (<i>b</i>) class of DNA mutation (ranging in scale from single base pairs to multiple chromosomes), (<i>c</i>) developmental context, (<i>d</i>) body location(s), (<i>e</i>) functional consequence (including deleterious, neutral, or advantageous), and (<i>f</i>) additional sources of mosaicism, including mitochondrial heteroplasmy, exogenous DNA sources such as vectors, aAnnual review of geneticsMosaicism in Human Health and Disease.PMC8483770P50 HD103538U01 MH106884U54 HD079123Tupler RPevsner JThorpe JAvigdor BEOsei-Owusu IAfalseMosaicism in Human Health and Disease.Mosaicism refers to the occurrence of two or more genomes in an individual derived from a single zygote. Germline mosaicism is a mutation that is limited to the gonads and can be transmitted to offspring. Somatic mosaicism is a postzygotic mutation that occurs in the soma, and it may occur at any developmental stage or in adult tissues. Mosaic variation may be classified in six ways: (<i>a</i>) germline or somatic origin, (<i>b</i>) class of DNA mutation (ranging in scale from single base pairs to multiple chromosomes), (<i>c</i>) developmental context, (<i>d</i>) body location(s), (<i>e</i>) functional consequence (including deleterious, neutral, or advantageous), and (<i>f</i>) additional sources of mosaicism, including mitochondrial heteroplasmy, exogenous DNA sources such as vectors, a2020-01-01T00:00:00Z2020 Nov2025-04-05T09:54:43.289Z2022-02-11T11:46:33.872ZS-EPMC84837703291607910.1146/annurev-genet-041720-093403