Overo Lethal White Syndrome (OLWS) is a fatal autosomal genetic disorder in American Paint Horses. It is caused by a specific dinucleotide mutation in the endothelin receptor type B (EDNRBEDNRBEDNRB) gene.
A breeder wishes to manage their herd to avoid foal mortality while still producing desirable coat patterns. Which of the following statements is incorrect regarding the genetics and inheritance patterns of this trait?
A cross between two frame overo horses is expected to produce a phenotypic ratio of 2 frame overo offspring to 1 solid-coloured offspring among the surviving horses.
The mutation of the EDNRBEDNRBEDNRB gene exhibits pleiotropy, as a single genetic alteration simultaneously affects both coat pigmentation and the development of the enteric nervous system.
Because the lethal white phenotype is recessive, mating a frame overo horse with a solid-coloured horse has a 25% probability of producing a foal with Overo Lethal White Syndrome.
If the breeder systematically avoids mating two frame overo horses together, the incidence of Overo Lethal White Syndrome in the offspring can be reduced to 0%, even if carrier horses continue to be bred.
