PKU.com Community Discussion Forum Parent support could genetic test help ?

Viewing 13 posts - 1 through 13 (of 13 total)
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  • #9319
    Avatar of medina
    medina2009
    Participant

    I want to ask whether genetic test now after bringing a child , could be useful for pku family ?
    and if it is useful , how could  help to the family ? 
    here , they wanted from all pku family to do genetic test and they told us its useful for your family . the price of this test is so high . I want to know really its useful ?

    #9321
    Avatar of Apostolia
    foufouka
    Member

     We had the genetic test when my daughter was 6 months old (here, it is done for free).

    They do a test to the little one, to know which two of the 400 mutations is the child carrying (one of each parent). A mutation is a small change to the DNA of the parents that can cause the deficiency of the enzyme, when it is present to both parents.

    There are almost 400 known mutations, each one having a different severity. So, from what I understand, if you do the genetic test you can

    i) predict the severity of the disorder. (This is not always the case, as doctors say that the only way is to test your child's tolerance by diet) and

    ii) predict 
    when you're pregnant weather the second child will have the PKU, doing an amnioparacentesis.

    You decide if this knoweledge is usefull to you or not.

    I hope this helps.

    #9322
    Avatar of medina
    medina2009
    Participant

    thanks alot for your reply foufoka . but I dont yet understand the benefit of genetic test . because you said that with this test you can predict the severity of the disorder .  but I know that my child have pku and no test can reduse the severity of disease , just he should have a diet to control his pku .

    and if we want to have another child again this test cant help us , because we are the carrier of this defect . and in every pregnancy , we have 25 percent the chance of having a pku child .

    So, I think doing genetic test for the family such us is wasting the time .

    #9323
    Avatar of Tanya
    jakesmom
    Member

    Jacob has had the blood drawn, and we are currently waiting on the results of the test for him. (Like Foufoka, it is done for free here, in Ontario) My understanding is that once they know exactly what mutation he has, it will assist in knowing how he can be treated best. Yes, diet will be important, but it is our understanding, it will also help predict better which diet restrictions are best.

    Originally we were told that Jacob's levels were low enough, that most likely he would only need monitoring until he was 5 years old, and then would be discharged from our clinic (assuming treatment guidelines in 5 years are what they are today) Low and behold, we are now on a diet, and monitoring is MUCH more frequent then originally anticipated. I understand it will take some of the surprises out of his/our future when it comes to PKU.

    From there, once they know Jacob's strain, they also stated they can further test his biological mother and father (friend was donor in our case). This can give valuable information to our friends other children, who show no signs of the disorder, however, are likely carriers. It is also information that my partner can share with her siblings who may also be carriers.

    This all being said, I am not sure it would be a step we would quickly jump to if the fees for the test came out of pocket, and not from government programs. I may have more information once we see and fully understand the results of the test, but that may be a few weeks or so to go. Thought I would share what I had at this time. Hope it helps.

    #9324
    Avatar of medina
    medina2009
    Participant

    thanks for your reply Jakesmom .  but this sentence : it helps which diet restrictions are best . what does it mean ?

    you mean that according to the result of these tests we can understand that  for example , for my child dairy is worse than grain? or viceversa .

    #9325
    Avatar of Apostolia
    foufouka
    Member

     I guess it means wether your child can have 250, or 400 or 500mg of phenylalanine, no matter what the source of the protein is. As for the severity it reflects if she has mild, moderate or severe PKU. Some people have some enzymic activity, which even it is low, it allows them to eat some more protein than othes with the more severe form of the disease. 

    As for the test during pregnancy, sorry for my english but what I meant was that when you're  pregnant they test the blood of the embryo and know wether it has PKU or not. They cannot do this if they don't know which mutation you're carrying. If you ask me, I wouldn't care to know it. But for some people could be important.

    #9327
    Avatar of Tanya
    jakesmom
    Member

    My thoughts were, like foufouka said, it will tell us how much phenylalanine he can have. Taking the guess work out of the diet. I hadn't given any thought to if it meant which source of protein.

    They originally thought he was HyperPHE, however, now say he is Mild PKU, which again, from my understanding, are slightly different. This test will give the us the answer as to what exact form he has, so we aren't worrying that it changed once, will it change again.

     

    From my understanding it can also let us know if medication (like Kuvan) would be an option available to him. Would his levels be reduced by it, and cause less of a restriction on food. (This can also be done by another test which checks Phe levels before and after administration of BH4. He had this test early on, although the drug is not being approved for him at this time, we are aware this will work for him in the future should we decide its needed.)

    We will likely know and understand more once we get the results. It was explained using broad terms of will help with what diet restrictions are necessary, it will help us in knowing how to best treat Jacob. I am almost embarrassed to admit, that because to us, it was little more than a draw of blood for Jacob, we agreed almost blindly. I can see how you would want/require more questions to your answers when you have to factor in dollars, expecially when the costs of feeding PKU children can already be a struggle.

    #9336
    Avatar of medina
    medina2009
    Participant

    thank you very much from both of you foufouka and jakesmom .  you gave me very complete explanation .

    In Iran , they said these tests is just for specifying the kind of mutation . and not the kind of pku or the amount of phe that the body can tolerate or the kind of treatment . and just is useful for when you want to have another child for amnioparacentesis and I dont know wether it has worth or not ? because even I would understand that my germ has pku , I wont abort him or her .

    #9338
    Avatar of Tanya
    jakesmom
    Member

    I will be sure to let you know exactly what we find out when we get the results. I don't think they will take too much longer to arrive. I am worried that I have assumed information, that isn't actually fact. But I am certainly providing you what I believe to be true.

    I know the test for both countries would be the same test, but I wonder if how they use the information differs. Maybe (here) they get more information, as they do more with the results then they do in Iran. I apologize if this statement sounds ignorant, it is simply a lack of information on my part how other countries utilize the medical stuff. I was so upset when I read on another site, how China views the children with PKU, and what little assistance they provide to their families. (or at least the mom that was posting)

    #9377
    Avatar of Natasha
    pkuparent2
    Member

    Hi there! Our son just had his blood drawn at the hospital yesterday for the genetic testing. We understood that it would help determine whether or not he would be a responder to Kuvan when he is old enough. They took a lot of blood and I believe it gets sent to Montreal. We were told it would take months to know anything. We'll keep our fingers crossed. It was free for us also in Canada.

    #9379
    Avatar of Tanya
    jakesmom
    Member

    Ok, I recently talked to the nurse, and asked a couple more questions for you medina.

    They did the genetic testing on Jacob in Nov I believe. At last check, the results are due back mid-feb.

     

    I am getting more and more confused as I get more information. When I asked recently if it specifically affects how he is treated (the results) they said not really as they are already treating him now, and if its working, they wont typically mess with it. (unless it shows drastic reasons).

     

    It can say if Kuvan may help, as it will narrow down exactly what the mutation is, however, Jacob had another test, which showed he was a 'likely canditate for the meds. The dr said until it is funded in Canada, she wont put any patients on it. Its VERY expensive. I think she was saying something like $30/pill, and adults can take up to 10 pills a day!! So, I am still somewhat confused as to why they do the test for this purpose when he has had another test they used to determine this. 

    They described the reason for the test, was it helps narrow down what the mutation is. She explained it as, if they handed me a book and asked for a specific word to be found, it would be very difficult. However, this test, tells me what page to look on, making it easier. This is the same for them, as it tells them where in his DNA the mutation is, so they know easier what they are looking for, and are able to find it. They will know the particulars of Jacob's disease.

    However, they also said, after testing him, they will test his biological mom and our Donor. This way, if her sisters, or his kids want the information, they will have it. I do know that it will tell us if he made the mutation, or if it was genetic. And can help in future family planning, for us, my sister-in-laws, as well as donor's female children.

    For Jacob thou, I don't see any major benefit.  I may not have chosen to do this test, if I had to pay for it, and it was only for other children if we weren't planning on having any.

    Saying that, if it helps one lil bit, I am happy they are doing it, as it is free for us, and only required blood work for jacob.

    Hope this helps

    #9380
    Avatar of carrie
    clenk
    Member

     In a short answer- no- genetic testing doesn't help you manage pku. 

    By the time you get the testing done you will have figured out the levels of PHE needed to keep numbers in range . They will fluctuate with illness, growth spurrts, exercise , etc. 

    Once you learn the exact mutation you will not change what you are doing. What is useful is if you are trying to get pregnant and you are pku and you and your partner get tested you can find out how likely it is for the child to be pku and how severe it might be. 

    If you have to pay out of pocket i'd save my money and invest in more low pro foods! 

    #9386
    Avatar of medina
    medina2009
    Participant

    thank you very much for your extreme kindness to share your information . they are so useful for me .  I just have a question about clenk writing . this test determine the severity of pku in germ when you are pregnant . are you sure ?

    because they said to us when you will be pregnant and do the test , they just will tell that your germ has pku or not and never say anything about the model of pku like mild , classic or hyperphe .

Viewing 13 posts - 1 through 13 (of 13 total)
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