Now, we'll cover cystic fibrosis.
Cystic fibrosis is a genetic disease
meaning it's caused by a person's genes.
It mainly affects the lungs and the
digestive systems in the body,
causing breathing problems and
problems digesting foods.
Cystic fibrosis affects the glands
that produce mucus and sweat.
These are the lungs and the GI tract.
The mucus is going to
become thick and sticky.
Lung infections can develop and lung
functioning decreases over time.
And unfortunately, currently,
there is no cure.
Cystic fibrosis affects at least
30,000 people in the United States.
All newborns are screened
for cystic fibrosis
on part of their required newborn screen.
The life expectancy of a patient with
cystic fibrosis is 30 or 40 years.
Some patients live beyond this.
Cystic fibrosis ultimately
results in respiratory failure.
So, every person has 2 copies
of the cystic fibrosis
transmembrane conductance regulator gene.
We'll refer to this as the CFTR gene.
Cystic fibrosis is an autosomal
so a person must inherit 2
mutated copies of the CFTR gene,
1 from each parent, to have cystic fibrosis.
This pedigree on the left,
both parents are carriers.
So we can see as they have their offspring,
their children will have a 25%
chance of having cystic fibrosis.
This is the child on the left.
They've inherited both mutated genes.
Now, this family will have a 50% chance
with each pregnancy of having a child
who is a carrier for cystic fibrosis,
and they'll also have a 25% chance of
having a completely unaffected child.
So the child will not be a carrier
and will not have cystic fibrosis.
Another situation would be if
1 parent has cystic fibrosis,
so they have 2 mutated copies of the gene,
and 1 parent is a carrier
with 1 mutated copy.
This family's going to have
a 50% percent chance
of having a child with cystic
fibrosis, which inherits both genes,
and 50% chance that their
children will be carriers.
So, mucus is a slippery
substance that lubricates
and protects the linings of the
airways, digestive system,
reproductive system, and
other organs and tissues.
In patients with cystic fibrosis,
the body is going to produce mucus
that is abnormally thick and sticky,
and this is going to lead to lots
of problems around the body.
In the sinuses, this can
contribute to sinusitis,
which is infection and
inflammation in the sinuses.
In the lungs, the patients are going
to have thick, sticky mucus buildup,
and this is a good place
for bacterial infection.
In the skin, the sweat glands
can produce salty sweat.
In the liver, the biliary duct
can get blocked by mucus.
The same thing can happen in the pancreas.
In the intestines, they're going
to get filled up with mucus
and they cannot fully absorb nutrients.
The reproductive organs are also
going to get backed up with mucus,
and this can cause problems with
fertility or delayed puberty.
On the top here, you'll see a normal airway
in a patient without cystic fibrosis.
Their airway wall is smooth and it's going
to be lined with a thin layer of mucus.
This is in contrast to a
patient with cystic fibrosis.
Their airway is going to become widened
and there's going to be thick, sticky
mucus that's going to block their airway.
The patient may have blood in their mucus
and this is a great breeding
ground for bacterial infection.