Mukowiscydoza testy genetyczne

[powiek89]

czy jest sens robić taki test genetyczny u 30 latka? Czy odkryje sie
nieprawidłowy gen, bo podobnież te badania wykrywają tylko jakiś
procenty tych nie prawidłowych genów? Czy wie ktoś jaka jest ich
skuteczność?

[osmanthus]

W USA wyglada to tak:

Prenatal diagnosis
Couples who are pregnant or who are planning a pregnancy can
themselves be tested for CFTR gene mutations to determine the
likelihood that their child will be born with cystic fibrosis.
Testing is typically performed first on one or both parents and, if
the risk of CF is found to be high, testing on the fetus can then be
performed. Cystic fibrosis testing is offered to many couples in the
US.[23] The American College of Obstetricians and Gynecologists
(ACOG) recommends testing for couples who have a personal or close
family history. Additionally, ACOG recommends that carrier testing
be offered to all Caucasian couples and be made available to couples
of other ethnic backgrounds.[24]
Because development of CF in the fetus requires each parent to pass
on a mutated copy of the CFTR gene and because CF testing is
expensive, testing is often performed on just one parent initially.
If that parent is found to be a carrier of a CFTR gene mutation, the
other parent is then tested to calculate the risk that their
children will have CF. CF can result from more than a thousand
different mutations and, as of 2006, it is not possible to test for
each one. Testing analyzes the blood for the most common mutations
such as ΔF508 — most commercially available tests look for 32 or
fewer different mutations. If a family has a known uncommon
mutation, specific screening for that mutation can be performed.
Because not all known mutations are found on current tests, a
negative screen does not guarantee that a child will not have
CF.[25] In addition, because the mutations tested are necessarily
those most common in the highest risk groups, testing in lower risk
ethnicities is less successful because the mutations commonly seen
in these groups are less common in the general population. These
couples may therefore consider testing through labs that offer CF
screens with a high number of mutations tested.
Couples who are at high risk for having a child with CF will often
opt to perform further testing before or during pregnancy. In vitro
fertilization with preimplantation genetic diagnosis offers the
possibility to examine the embryo prior to its placement into the
uterus. The test, performed 3 days after fertilization, looks for
the presence of abnormal CF genes. If two mutated CFTR genes are
identified, the embryo is not used for embryo transfer and an embryo
with at least one normal gene is implanted.
During pregnancy, testing can be performed on the placenta
(chorionic villus sampling) or the fluid around the fetus
(amniocentesis). However, chorionic villus sampling has a risk of
fetal death of 1 in 100 and amniocentesis of 1 in 200,[26] although
a recent study has indicated this may actually be much lower,
perhaps 1 in 1,600,[1] so the benefits must be determined to
outweigh these risks prior to going forward with testing.
Alternatively, some couples choose to undergo third party
reproduction with egg or sperm donors

[scept89]

powiek89 napisał:
> czy jest sens robić taki test genetyczny u 30 latka?

1) Sens w znaczeniu: rozpoznanie mukowiscydozy? Nie. Malo
prawdopodobne aby ktos dozyl 30rz bez rozpoznanej klinicznie
mukowiscydozy w postaci typowej.

22) sens w znaczeniu: sprawdzenie czy nie jestem nosicielem?

Chyba tylko wtedy jesli w rodzinie wystepowaly przypadki
mukowiscydozy.

>Czy odkryje sie
> nieprawidłowy gen, bo podobnież te badania wykrywają tylko jakiś
> procenty tych nie prawidłowych genów?

Jest mutacja (zmiana) w calkiem prawidlowym genie.
pl.wikipedia.org/wiki/CFTR
Mutacji w/w jest wiele ale w Europie dominuje delta-F508. IMHO kazda
europejska pracownia genetyczna testuje wlasnie ta mutacje, ale jesli
do wykrywania mutacji stosowane jest sekwencjonowanie DNA to sa
zdolni wykryc takze kilka innych niejako "z marszu".