de novo allele origin [GENO_0000880]

de novo allele origin

ID: GENO_0000880

Describes an allele that originated through a mutation event in a germ cell of one of the parents, or in the fertilized egg itself during early embryogenesis. De novo alleles are* heritable* but *not inherited*.

We distinguish germline, somatic, and de novo allele origin based on a combination two key criteria - whether the allele *inherited* from a parent, and whether it is *heritble' by offspring. De novo variants are *heritable* but not *inherited* - as they are not observed constitutively in either parent, but can be passed to offspring in virtue of their being present in the individual's germ cells. By contrast, germline variants are both inherited (passed down from a parent) and heritable (passable down to offspring), and somatic variants are neither inherited or heritable - having originated via a spontaneous mutation in a non-germ cell. De novo variants appear for the first time in one family member. They often explain genetic disorders in which an affected child has a mutation in every cell in the body but the parents do not, and there is no family history of the disorder.