介绍:
Who's Your Daddy? The Answer May Be at the Drugstore
It is a wise father that knows his own child,
but today a man can boost his paternal wisdom
---or at least confirm that he's the kid's dad.
All he needs to do is shell out $30 for
a paternity testing kit (PTK) at his local drugstore
---and another $120 to get the results.
More than 60,000 people have purchased the PTKs
since they first became available
without prescriptions last year,
according to Doug Fogg, chief operating officer of Identigene,
which makes the over-the-counter kits.
More than two dozen companies sell DNA
tests directly to the public, ranging in price
from a few hundred dollars to more than $2,500.
Among the most popular: paternity and kinship testing,
which adopted children can use to find
their biological relatives and families can use to
track down kids put up for adoption.
DNA testing is also the latest rage
among passionate genealogists---and supports businesses
that offer to search for a family's geographic roots.
Most tests require collecting cells by swabbing saliva
in the mouth and sending it to the company for testing.
All tests require a potential candidate
with whom to compare DNA.
But some observers are skeptical.
"There's a kind of false precision being hawked
by people claiming they are doing ancestry testing,"
says Troy Duster, a New York University sociologist.
He notes that each individual has many ancestors
---numbering in the hundreds just a few centuries back.
Yet most ancestry testing only considers a single lineage,
either the Y chromosome inherited through men
in a father's line or mitochondrial DNA,
which is passed down only from mothers.
This DNA can reveal genetic information
about only one or two ancestors, even though,
for example, just three generations back people
also have six other great-grandparents or,
four generations back, 14 other great-great-grandparents.
Critics also argue that commercial genetic testing is
only as good as the reference collections
to which a sample is compared.
Databases used by some companies don't rely
on data collected systematically
but rather lump together information
from different research projects.
This means that a DNA database may have a lot of data
from some regions and not others,
so a person's test results may differ
depending on the company that processes the results.
In addition, the computer programs a company uses to
estimate relationships may be patented
and not subject to peer review or outside evaluation.
