Alfred Kudson Theorizing The Two-Hit Syndrome

Alfred Kudson studied retinoblastoma, a type of retina tumor that can develop on two different ways and under different conditions. The sporadic form occurs when the affected children present a single tumor in one of the eyes, and no family history for the disease is recorded. On the other hand, on the familial form, children have various tumors in both eyes and one of their parents had the disease.
Analyzing the genetic characteristics of both retinoblastoma’s types, mainly the mutations on a tumor suppressor gene named Rb, Kudson theorized the “two-hit hypothesis”. He stated that sporadic retinoblastoma arises through the gaining of two new random somatic mutations. In contrast, the familial form demands only one somatic mutation to develop,