Newsgroup: it.scienza.medicina
Titolo: DNA Paternity Test nei supermercati USA

Da quanto apprendo, negli USA � in vendita per 40 dollari o gi� di l� nei 
supermercati.
 
Vedi la controversia quando sono stati introdotti in commercio:
 
http://www.msnbc.msn.com/id/23814032/ns/health-womens_health/t/whos-your-daddy-answers-drugstore/
 
...
But for genetics experts, drugstore marketing of DNA testing raises 
questions of accuracy and ethics.
 
"From our perspective, direct-to-consumer genetic tests raise all the same 
issues for lax government oversight, potentially misleading or false 
advertising and the potential for making profound medical decisions on the 
basis of poorly interpreted or understood results," said Rick Borchelt, a 
spokesman for the Genetics and Public Policy Center at Johns Hopkins 
University.
...
 
D'altra parte, per
...
 Michael S. Watson, executive director of the American College of Medical 
Genetics.
 
Unlike genetic tests for health conditions, tests that use DNA to determine 
paternity are fairly simple to provide and fairly easy to interpret, said 
Watson. They're subject to limited oversight, however, with no review 
required by the Food and Drug Administration and no certification required 
under the federal Clinical Laboratory Improvement Amendments, or CLIA.
 
The Identigene kit includes swabs for collecting cell samples from the 
inside of the cheeks of the child and the alleged father. Collection of the 
mother's cells is optional, but strongly recommended to strengthen the 
results. The swabs are packaged and mailed to the Sorenson laboratory in 
Salt Lake City where they're analyzed.
 
The Sorenson lab is accredited by the AABB, the agency formerly known as the 
American Association of Blood Banks.
 
Results are reported online, by phone or by mail in three to five business 
days. They come back as a probability figure that verifies paternity with 98 
percent to 99 percent accuracy, Watson said.
... 

 percent to 99 percent accuracy, "
 
 
Ecco....
Questo � male!
Cosa vuol dire "accuracy"?? Ci sono _almeno_ 4 grandezze statistiche
diverse per valutare quella che "intuitivamente" si chiama
"accuratezza" di un test. E non son banali da capire nelle
implicazioni.
Calcolando che gli addetti del settore confondono facilissimamente la
propobilit� di un effetto data la causa e la probabilit� di causa dato
un effetto figuriamoci cosa pu� capire il bifolco dello Utah che
compra sta cosa al supermercato...
 
Non mi stupirei se esistessero classi di casi in cui d� risultati
totalmente fuorvianti.  (son pronto a scommetterci che nel caso in cui
il test dice: "non � il padre" questo possa sbagliare con altissime
probabilit�, anche se con "accuracy between 98 an 99%" intendessero
sia sensitivit� che specificit�. Cosa che comunque dubito)

 sia sensitività che specificità. Cosa che comunque dubito)
 
 
Vabbe', se non è il padre... magari è lo zio! ;-)
 
Scherzi a parte, in effetti sono concetti che andrebbero chiariti. Mi par di 
capire che il test di paternità non possa, per sua natura, dare certezze del 
100 nel senso della conferma di paternità, ma possa avvicinarsi al 100 
percento se invece si cerca conferma dell'esclusione, cioè che non sia 
quello il padre. Giusto?
 
Leggo in questa discussione americana...
http://www.truthaboutdeception.com/community-features/ask-an-expert/questions-by-topic/relationship-issues/867-how-accurate-is-paternity-testing.html
 
...
There are, however, results that cannot be contested in a court of law due 
to the overwhelming nature of the results. There are two forms of paternity 
testing results - the exclusion and the inclusion.
 
The exclusion paternity test can be considered 100% accurate. The DNA from 
the baby is tested against the DNA of the father. The father is responsible 
for ½ of the chromosomes in the baby's DNA and thus the test will exclude a 
father than does not have any matching pairs of chromosomes with the baby.
The inclusion paternity test is a bit different. The results of the 
inclusion paternity test will tell how likely the father is to be the 
biological match with the baby. In most cases, the results will appear as a 
percentage. The best percentage is 99% and above.
The results of the paternity test are determined by the number of loci 
pulled from the donors. The best test results come from a paternity test 
using 16 loci. The loci are another name for DNA match points. Some 
paternity testing facilities will only test 13 loci. This test results will 
be less accurate than a test using 16 loci.