Chapter 23.1, Problem 3TPSQ

a.

Summary Introduction

To determine:

The probability that another child of the couple will have retinoblastoma.

Introduction:

Alfred Knudson in 1971, proposed a model to explain the genetic basis for cancer. He was studying retinoblastoma (develops in one eye but sometimes appears in both) and proposed that retinoblastoma results from separate genetic defects mainly two and both of which are required for the development of cancer. Mutations in the cells of a single eye results in “unilateral retinoblastoma” which is common and can occur to a normal person.

Mutations in the cells of both eyes result in “bilateral retinoblastoma” which is rare and cannot happen randomly like unilateral retinoblastoma. Individuals inherit the only single mutation from suffering relatives and if the second mutation occurs in any of these cells then it would result in bilateral retinoblastoma.

b.

Summary Introduction

To determine:

Whether the next child has unilateral or bilateral retinoblastoma.

Introduction:

Alfred Knudson in 1971, proposed a model to explain the genetic basis for cancer. He was studying retinoblastoma (develops in one eye but sometimes appears in both) and proposed that retinoblastoma results from separate genetic defects mainly two and both of which are required for the development of cancer. Mutations in the cells of a single eye results in “unilateral retinoblastoma” which is common and can occur to a normal person.

Mutations in the cells of both eyes result in “bilateral retinoblastoma” which is rare and cannot happen randomly like unilateral retinoblastoma. Individuals inherit the only single mutation from suffering relatives and if the second mutation occurs in any of these cells then it would result in bilateral retinoblastoma.

c.

Summary Introduction

To determine:

The reason corresponding to that father has unilateral retinoblastoma while in his son’s and brother’s case it is bilateral retinoblastoma.

Introduction:

Alfred Knudson in 1971, proposed a model to explain the genetic basis for cancer. He was studying retinoblastoma (develops in one eye but sometimes appears in both) and proposed that retinoblastoma results from separate genetic defects mainly two and both of which are required for the development of cancer. Mutations in the cells of a single eye results in “unilateral retinoblastoma” which is common and can occur to a normal person.

Mutations in the cells of both eyes result in “bilateral retinoblastoma” which is rare and cannot happen randomly like unilateral retinoblastoma. Individuals inherit the only single mutation from suffering relatives and if the second mutation occurs in any of these cells then it would result in bilateral retinoblastoma.