Complex sentence: Somatic gene conversion is one of the mechanisms that can result in familial retinoblastoma, a congenital cancer of the retina, and it is theorized that gene conversion may play a role in the development of Huntington's disease.
Split into simpler sentences: Somatic gene conversion is one of the mechanisms that can result in familial retinoblastoma, a congenital cancer of the retina. It is theorized that gene conversion may play a role in the development of Huntington's disease.