Mosaicism is the name given to a type of genetic failure during the development of the embryo within the mother’s uterus, in which the person begins to have two distinct genetic materials, one formed by the egg binding with the sperm of the parents, and another that results from a mutation of a cell during the development of the embryo.
Thus, the person will develop a mixture of cells, with a percentage of normal cells and another percentage of cells with the mutation, as shown in the following figure:
- Mosaicism occurs when a mutation occurs in an embryonic cell.
- Usually the loss or duplication of a chromosome.
- Which causes the person to develop their body with 2 types of cells and 2 types of genetic material.
- This mutation can be of 2 types:.
Mixed mosaicism occurs when the person presents both types of mosaicism, both germline and somatic.
Mosaicism differs from chimerism in that, in this situation, the genetic material of the embryo is duplicated by the fusion of two different embryos, which are one. Learn more about this situation in chimerism.
Although many cases of mosaicism do not cause symptoms or consequences for a person’s health, this situation can lead to various complications and diseases for the carrier, and some examples include:
In addition, mosaicism has been observed to increase susceptibility to degenerative neurological diseases, such as Alzheimer’s or Parkinson’s disease, for example.