The prevalence of diagnosed cases of chimerism depends on the specific type. The majority of individuals with chimerism remain undiagnosed, so we are not sure how many people have this condition.
Consequently, most remain undiagnosed throughout their lifetime, partly because the condition is not well known in the medical community, and partly because there is no population-wide screening practice. Most individuals with chimerism have no idea they have a second genome. A baby born to an individual with chimerism can be more distantly related from a genetic perspective, as if they were a niece/nephew. )Ĭhimerism doesn’t usually have many signs or symptoms, but if people with the condition aren’t diagnosed an unexpected outcome may occur when they have children.
(Scientifically speaking, this type of chimerism is called tetragametic because the baby was derived from four gametes – one egg and one sperm for each embryo. Chimerism occurs when a woman is pregnant with twins and one embryo dies, and the other embryo absorbs the twin’s cells. Now at 33 years old, Muhl, a musician and model, understands her two-toned skin is actually a result of a genetic condition called chimerism, which causes an individual to have two genomes, or sets of DNA. When Taylor Muhl was born, her mother was told that her baby’s two-toned skin was a birthmark.