Question

What is the Pleiotropism? Give an example.

Answer 1

Pleiotropism is the condition in which a single gene controls more than one phenotypic effect, that is completely unrelated. E.g.: Phenylketonuria. It is an autosomal recessive disorder affecting chromosome number 12. A defect in the chromosome leads synthesis of tyrosine instead of phenylalanine and some of the symptoms of the disease are: mental retardation, decreased pigmentation of hair and skin and eczema.