Case Workbook for Human Genetics 9th Edition by Ricki Lewis

Exercise 3

In retinitis pigmentosum, cells at the back of the eye receive light and signal the part of the brain that provides vision. Seven genes encode proteins that are part of the light-receiving parts of these cells. Is retinitis pigmentosum genetically heterogeneic, incompletely penetrant, sex-linked, or variably expressive?