Chapter 25, Problem 5CONQ

Summary Introduction

To review:

Whether the statements are accurate with regard to the genetic basis of human disease.

A. Two copies of a mutant allele should be inherited to have a disease.

B. Genetic predisposition refers to an individual who has inherited more than one allele that results in the development of the disease.

C. Genetic predisposition related disease may be passed from parent to offspring.

D. The genetic basis of a disease is always more important than itsenvironment.

Introduction:

Phenylketonuria (PKU) is a genetic disorder which is inherited by the offspringfrom parents. Mutation in the PAH (phenylalanine hydroxylase) gene is the reason for PKU, and results in decreased levels of enzyme phenylalanine hydroxylase. It is an inborn error of metabolism. Another genetic disorder is achondroplasia. It is a genetic disorder where anindividual isa dwarf and it is caused by amutation in the fibroblast growth factor receptorgene.