FREQUENTLY ASKED QUESTIONS
When can the CFTR gene cause problem, how does the disease develop?
The CFTR gene is present in everyone. Since every gene we have, except those on the sex chromosomes, is present in two copies we have two copies of the CFTR gene as well. The CFTR protein, which controls the movement of salts and water through the cell membrane, is transcribed and produced indirectly from these genes. If one of the copies is defective, the amount of correctly functioning proteins decreases, but this does not necessarily lead to health damage. However, if both copies carry the mutation the disease develops. As in Hungary one in every 28 people carries a defective copy of the CFTR gene, there is a high probability that the child to be born will inherit the defective copy from his/her parents.
Can everyone be a carrier of cystic fibrosis?
Yes, both sexes are affected by the disease at equal frequency.
What is the prevalence of cystic fibrosis?
In Hungary, one in every 28 people is a carrier of a CFTR mutation, and the disease manifests in about one out of every 2500 babies born. This means that, on average, 40 babies suffering from CFTR are born every year in Hungary.
When do the symptoms of the disease appear?
The symptoms can appear at any age, but they manifest most frequently already in the first few years of life affecting mainly the respiratory or the digestive system. After birth, in about 15% of the cases, ileus indicates the problem. It is worth paying attention to symptoms such as recurrent coughing and/or pulmonary infiltration and lag of physical development already from birth.
What other effects does the disease have?
Fortunately, intelligence is not influenced by the disease. However, it may have serious consequences for fertility. Depending on the mutation, fertility may be impaired even in carriers. This accounts for 1-2% of male infertility, which is important to know because the disease impairs only the release of sperms; thus, participation in assisted reproduction programmes can be successful. In case of infertility, the board of clinical genetics suggests testing the CFTR gene.
I am planning to have a family; should I have a test?
Testing is particularly indicated in both parents before having children because one in every 28 people, that is, 4% of the population is asymptomatic carrier. If two carriers have a child, they have a 25% probability that their child will be ill. If someone suffers from the disease in the family, there is a higher-than-average risk for the baby to be born with cystic fibrosis.
How efficient is the test; does it surely detect the mutation?
The CFTR gene is 230 000 base pair long, and mutations have been described in nearly 2000 positions. The frequency of these mutations varies over a wide range. Screening tests focus on those positions that are present in at least 1% of the population, thus, rare variations remain hidden. In contrast, the CE IVD certified test we use identifies all the mutations, regardless of their frequency by reading the whole coding sequence of the gene.
What should I do to have the test performed?
You only have to contact our genetic counsellor who will be glad to give you advice on whether the test is recommended for you or for a member of your family. If it is recommended, a simple blood draw is enough for the test.
When can I expect to have the result?
The result is ready within 4-6 weeks of sample taking; our genetic counsellor will contact you and provide all the information necessary for the interpretation of the result and for the further steps if required.