Module 6 Mini Lesson 1 Self-Check

Which systems are most commonly affected by mutations in the CFTR gene?

Kidneys and long bones
Incorrect
Lungs and pancreas
Correct! The lungs and pancreas are the most affected organ system in classic CF.
Brain and muscles
Incorrect.
Heart and intestines
Incorrect

If the CFTR mutations R1117 and 5T are on the same allele, they are said to be:

In cis
Correct! When mutations are on the same allele for the CFTR gene locus, they are said to be in cis.
In trans
Incorrect.
Hemizygous
Incorrect.
Wild type
Incorrect.

Different mutations in the same gene may cause different phenotypes because:

Some types of mutation affect the size of a protein chain.
Incorrect.
Some types of mutations affect the amount of protein made.
Incorrect.
Some types of mutations affect the functionality of a protein made.
Incorrect.
Some types of mutations cause no protein to be made at all.
Incorrect
All of the above.
Correct! Mutations in genes can affect the protein product in many ways. In many conditions, including CF, we have the capability of predicting phenotype (at least to some degree) based on genotype. The relationship between genotype and phenotype is called genotype/phenotype correlation. In CF, pancreatic insufficiency as an example. Based on genotype, we can often predict pancreatic even before birth. Genotype/phenotype correlation is an important genetics concept that can be applied to all disorders. Typically there is a closer and better defined correlation between genotype and phenotype in Mendelian or single gene disorders than in common complex disorders.