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Víctor Asensio has a PhD in biology and works at the Genetics Department of the Hospital Universitario Son Espases. In this informative capsule, Dr. Asensio will help us learn about the Cystic Fibrosis gene.
The heel prick test in Cystic Fibrosis
It all starts with the heel prick, the test that will mark the baby’s medical future. With a small blood sample, the hospital laboratory will do a screening with the immunoreactive trypsinogen test to detect those cases suspected of having Cystic Fibrosis.
The role of the Genetics Department
Between 7 and 10 suspicious samples arrive each week at the Genetics Department and there a DNA extraction is performed to look at the 50 mutations that prevail when diagnosing “classic” Cystic Fibrosis, that is, the one with the most common and recognizable symptoms. There is an international database that gathers all the mutations that have been described.
The Cystic Fibrosis gene
Currently, we know 2000 mutations affecting the gene, but not all of them will cause Cystic Fibrosis, so they are classified according to the frequency with which they occur in people with this disease.
Therefore, we can speak of mutations that cause Cystic Fibrosis, others that will cause a more attenuated Cystic Fibrosis (it presents some symptoms but does not meet the conditions of a classic one), others that are benign and others that it is not known what effects they produce.
Classification of CF gene mutations
On the other hand, mutations can be classified according to whether they modify the genetic code in one way or another. Therefore, knowing that DNA has the information to produce proteins, if the chromosome reads a letter or a word that is not correct, the production of the protein will be affected, either causing it not to perform its function correctly or it will not be able to synthesize the protein.
The effects of a read error, depending on where it occurs, can produce the following effects:
– That the protein localizes within the cell, such as F508del, but does not reach the cell surface.
– The protein is not synthesized because there is a so-called “stop codon”, i.e. a misplaced period in the genetic text.
– That the protein has the channel to reach the cell surface but does not open and does not facilitate its function.
Basic tool for the treatment for Cystic Fibrosis
It is very important to know the effects of these mutations for the treatment for Cystic Fibrosis, since drugs are studied individually for each type of mutation.
Currently, drugs such as Kaftrio attack the problem of mutations in which the protein is inside the cell, which is what it touches.
Its action can be focused on increasing the number of proteins that go to the surface or to open or increase the channel for the exchange of sodium and chloride ion.
Same mutations do not mean same reactions to infections
While it is logical that a family may be interested in the possible symptoms that their children will have in the future according to their mutations, Dr. Asensio discovers that Cystic Fibrosis is not only influenced by this gene, but also by the rest of the genetic code.
Therefore, it is likely that with the same mutations, each individual responds differently to infections or malnutrition. In addition, he points out that daily life, i.e. healthy or unhealthy lifestyle habits, also influences the response to these health disturbances.
Let’s enjoy the moments when Cystic Fibrosis gives a truce
The conclusion is that we should enjoy the periods in which Cystic Fibrosis respects our children and not think about whether they may have one symptom or another because the statistics say so.
Each person is different, so negatively anticipating possible situations that may never occur, only produces states of anxiety and restlessness that do not help the development of our daughter or son.
The individual is the focus, not statistics
The team of specialists focuses on the individual and not on the probabilities of having this or that symptom and will act on each specific symptom as it arises at the appropriate time.
We must trust medical judgment and, above all, enjoy motherhood or fatherhood in the good times, which will probably be much more frequent than the bad times.