Cystic Fibrosis: Genetics and CFTR

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the likely outcome for individuals with two copies of the Z allele (ZZ) in each cell?

They are likely to have alpha-1 antitrypsin deficiency. (correct)

They have a low risk of impaired liver function.

They have a high chance of developing cystic fibrosis.

They have a slight risk of developing lung diseases.

What is the estimated number of people worldwide with one copy of the S or Z allele and one copy of the M allele in each cell (MS or MZ)?

More than 161 million people (correct)

Over 100 million people

Less than 10 million people

About 50 million people

What is a symptom of cystic fibrosis?

Increased heart rate

Dehydration

All of the above (correct)

Weakness

What is the average lifespan of people with cystic fibrosis?

About 37 years Signup and view all the answers

Which country has the highest incidence of cystic fibrosis?

Ireland Signup and view all the answers

What is the probability of children of carrier parents having cystic fibrosis?

25% Signup and view all the answers

What is the relationship between the genes of parents and the development of cystic fibrosis in children?

Both parents must be carriers of the gene and then pass it on Signup and view all the answers

What is the incidence of cystic fibrosis among whites compared to people of other races?

More whites get cystic fibrosis than people of other races Signup and view all the answers

What is the estimated number of Americans who carry the cystic fibrosis gene without knowing it?

10 million Signup and view all the answers

What is the likelihood of developing asthma if one's parent has asthma?

Three to six times more likely Signup and view all the answers

What is the primary function of the CFTR protein in healthy individuals?

To aid in the transport of salt and water in and out of cells Signup and view all the answers

What is the most common mutation associated with cystic fibrosis?

A deletion of three DNA nucleotides, leading to the deletion of an amino acid (phenylalanine) at position 508 Signup and view all the answers

What is the term used to describe conditions caused by two CFTR mutations that result in mild lung disease with or without pancreatic involvement?

Atypical cystic fibrosis Signup and view all the answers

What is the chromosomal location of the CFTR gene?

Chromosome 7q31.2 Signup and view all the answers

What is the consequence of a defective CFTR protein in individuals with cystic fibrosis?

The blockage of salt movement in and out of cells, leading to abnormally thick, sticky mucus Signup and view all the answers

Study Notes

Cystic Fibrosis

Cystic fibrosis is caused by a defective gene on chromosome 7q31.2, called CFTR (cystic fibrosis transmembrane conductance regulator).
The CFTR gene produces a protein that helps salt (sodium chloride) move in and out of cells.
If the protein doesn't work correctly, an abnormally thick and sticky mucus is produced on the outside of the cell, clogging the airways in the lungs and increasing the risk of infection by bacteria.
The cells most seriously affected by this are the lung cells.
Over 2,000 mutations have been described that affect the CFTR gene in different ways.
The most common CFTR mutation is a deletion of three DNA nucleotides, leading to the deletion of an amino acid (phenylalanine) at position 508 of the protein sequence, denoted as ΔF508.
ΔF508 is found in around 90% of CF patients.
Some conditions caused by two CFTR mutations might cause only mild lung disease with or without affecting the pancreas, and can be described as "atypical CF".
Cystic fibrosis is an inherited disease, and both parents must be carriers of the gene for a child to inherit it.
25% of children of carrier parents will have cystic fibrosis.
Boys and girls are equally likely to get the disease.
About 10 million Americans carry the gene and do not know it.
More whites get the disease than do people of other races.

Sweat Test

In cystic fibrosis, mutations affect the composition of the mucus layer lining the epithelial surfaces in the lungs and pancreas.
The disruption of ion transport affects the salt concentration in sweat, which is used in the CF "sweat test".

Inheritance

For someone to get cystic fibrosis, both parents must be carriers of the gene that causes it.
Boys and girls are equally likely to get the disease.
About 10 million Americans carry the gene and do not know it.
More whites get the disease than do people of other races.

Asthma

Asthma is a chronic lung disease that causes wheezing, breathlessness, chest tightness, and coughing.
According to the Centers for Disease Control and Prevention, approximately 1 in 12 adults and 1 in 11 children have asthma.
Bronchial asthma is the most common chronic disease affecting children and young adults.
It is a complex genetic disorder with a heterogeneous phenotype, largely attributed to the interactions among many genes and between these genes and the environment.
Having a family history of asthma or allergies increases the chance of developing asthma.
Other risk factors for asthma include smoking or breathing in tobacco smoke, pollution, and obesity.

Alpha-1 Antitrypsin Deficiency

Individuals with two copies of the Z allele (ZZ) in each cell are likely to have alpha-1 antitrypsin deficiency.
Those with the SZ combination have an increased risk of developing lung diseases (such as emphysema), particularly if they smoke.
Worldwide, it is estimated that more than 161 million people have one copy of the S or Z allele and one copy of the M allele in each cell (MS or MZ).
Individuals with an MS (or SS) combination usually produce enough alpha-1 antitrypsin to protect the lungs.
People with MZ alleles have a slightly increased risk of impaired lung or liver function.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the genetic aspects of cystic fibrosis, including the defective gene on chromosome 7q31.2 and its impact on salt movement in and out of cells. Learn about the role of CFTR protein in this genetic disorder.