Could you
be a Cystic
Fibrosis Carrier?
Queensland Fertility
Group’s guide to Cystic
Fibrosis and Infertility
Public Information 1800 111 483
www.qfg.com.au
Given that many Cystic Fibrosis (CF) carriers are completely
healthy adults with no family history of the disorder, people
are often unaware that the carrier rate for CF is one in 25
individuals in the general population. If both parents carry a
CF mutation then the chance of having a child with CF is one
in four.
At Queensland Fertility Group, our CF screening program
identifies CF mutations at a rate of one in 24 female patients
and one in 14 male patients, based on over 6000 patients
tested. 18.5% of male CF carriers identified have the
CF mutation that is associated with infertility.
What is Cystic Fibrosis?
Cystic Fibrosis is an inherited genetic disorder that affects respiratory
and digestive systems from infancy through to adulthood. CF can
affect several organs in the body, and symptoms include a persistent
cough, difficulty breathing after physical exertion, tiredness and poor
appetite. CF causes the formation of thick mucus that traps bacteria,
resulting in infections that damage both the lungs and the gut.
Babies and children with CF need daily physiotherapy for their lungs
and frequent courses of antibiotics to treat the bacterial infections.
They also need medication to aid digestion. There is no cure for CF,
and until recently most people affected by the disorder died in early
childhood. With the range of treatment options currently available
many people live to 30-40 years of age.
Additionally, male CF carriers frequently have a mutated gene that
is associated with infertility. This mutation results in congenital
bilateral absence of the vas deferens, meaning that the vas deferens
(male reproductive organs) fail to develop properly prior to birth
and are unable to transport sperm from the testes into the ejaculate.
The condition where a male’s ejaculated semen does not contain any
sperm is known as azoospermia.
What is the risk of having a baby with CF?
All babies in Australia are screened for CF using a blood sample taken
three days after birth. Most babies carrying the genetic mutations that
cause severe CF symptoms are promptly diagnosed.
The gene associated with CF (the CFTR gene), however, was only
identified in 1989; the majority of adults have never been tested,
and their carrier status remains unknown.
CF is a recessive genetic condition. A baby inherits one CFTR gene
from each parent, and if both parents carry a mutated CFTR gene
then the chance of having a child with CF is one in four. About one
million Australians carry a gene mutation in one of their CFTR genes
as well as having a healthy copy.
CF can occur in all ethnic groupings, although the carrier frequency
is less (a rate of one in 90) for people of Asian descent. Why should
you be tested? Given that the CF carrier rate is higher in infertility
patients, and that many CF carriers are completely healthy adults
with no family history of the disorder, Queensland Fertility Group
recommends that at least one of the partners is screened for CF
prior to commencing any fertility treatments.
This screening not only provides the couple with an accurate
assessment of their chances of having a baby with CF, but it also
allows your Queensland Fertility Group specialist to determine
the most effective fertility investigations and treatments for
your situation.
Screening at Queensland Fertility Group
When screening for CF carrier status, Queensland Fertility Group
scientists look at the 30 most common genetic mutations, including
the mutations associated with infertility. Testing is completed at our
in-house Genetics Laboratory, using a blood sample taken after your
first appointment with your Queensland Fertility Group specialist.
To date, Queensland Fertility Group has screened over 6,000 patients
and identified a carrier detection rate of one in 24 female patients
and one in 14 male patients. Of those carriers detected 13.5% had
the mutation associated with infertility compared to the population
incidence of 0.3%.
If your CFTR mutation test identifies you as a CF carrier, your
Queensland Fertility Group specialist will recommend that your partner
should be tested and also refer you to a Clinical Geneticist, who will
discuss and fully explain your risk of having an affected child.
Your Queensland Fertility Group specialist will also discuss
diagnostic options including Preimplantation Genetic Diagnosis
(PGD) and prenatal diagnosis by CVS (chorionic villus sampling)
and amniocentesis.
Costs
Screening for CF mutations is not covered by Medicare. For the
current test fee, please contact your local Queensland Fertility Group
clinic. This expense can go towards out of pocket tax expenses.
CAIRNS
Queensland Fertility Group’s
Network of Care
www.qfg.com.au
1800 111 483
TOWNSVILLE
MACKAY
BRISBANE
IPSWICH
TOOWOOMBA
GOLD COAST
Brisbane
Auchenflower (Wesley Hospital),
Capalaba, City, Everton Park,
South Bank, Spring Hill
Ipswich
T [07] 4638 5243
T 1800 111 483
Mackay
T [07] 4965 6500
Cairns
T [07] 4041 2400
Toowoomba
T [07] 4638 5243
Gold Coast
T [07] 5564 8455
Townsville
T [07] 4772 8900
QFG-COMM-PI-004 18-03-2014
For more information on clinic and specialist locations or
Queensland Fertility Group’s regular public information events visit
www.qfg.com.au