A MODEL was shocked to discover that her unique two-tone skin colouring which she viewed as a ‘birthmark’ was actually the result of absorbing her own twin in her mother's womb. After battling autoimmune issues, Taylor Muhl from Los Angeles, California, was diagnosed with ‘chimerism’ - a condition in which a fraternal twin dies in utero and is fused into the surviving twin. As a result of her chimerism, Taylor has two sets of DNA, two sets of blood cells and two immune systems. Taylor's physical abnormality appears as a straight line that runs down the centre of her torso dividing it into two different colours - the left side of the pigmentation being her twin’s genetic makeup and the right side being her own.