DNA Paternity Testing
What is paternity testing?
Paternity testing can determine whether or not a particular man is the
biological father of a particular child. This procedure involves collecting and
examining the DNA of a small sample of bodily fluid or tissue from a child and
the alleged father. DNA is the unique genetic "fingerprint" that is present in
every cell of a human’s body. When a baby is conceived, each parent passes on
half of their genes contained in 23 chromosomes to the baby, whose genetic code
(46 chromosomes) is a shared mix of only its mother’s and father’s DNA.
By collecting and examining a small sample of DNA from the baby and the alleged
father, a paternity test can confirm or disprove that the alleged father is
indeed the biological father of the baby. (Note: To provide a complete DNA
picture, typically, a mother’s DNA is also collected and tested although this is
not absolutely essential for confirming or disproving the identity of the
father.)
What bodily fluids and tissues can be sampled?
DNA is present in most of our body’s cells. A small sample for testing can be
obtained from several bodily sources. The cells most commonly tested are
obtained from the blood or inside the cheek of the mouth (called buccal cells).
How is the cheek cell test conducted?
Cells are collected by gently rubbing a cotton swab – similar to a Q-tip - on
the inside cheek of the mouth. The swab is sent to a laboratory and a select
number of specific DNA sequences are examined to determine if the DNA collected
from the baby match DNA collected from the alleged father.
How accurate is DNA testing?
DNA testing is generally considered to be the most accurate testing method
available. DNA paternity testing can indicate that a man is highly likely to be
the father with about 99.9 percent accuracy or that he is excluded as being the
father with 100 percent accuracy.
Can paternity be confirmed before the baby is born?
Yes. Two different testing methods can be done while the baby is still
developing in the mother’s womb. One test, called chorionic villus sampling
(CVS), is conducted only between 10 to 12 weeks of pregnancy. This test involves
testing a small sample of tissue from the placenta. Another test, called
amniocentesis, is performed between 15 and 22 weeks of pregnancy. This test
involves passing a needle through the mother’s abdomen into the womb to withdraw
a small sample of amniotic fluid, which also contains cells from the baby. The
collected samples are then forwarded to a laboratory for examination. Although
technically possible to confirm paternity with these tests, the risk of
miscarriage – generally given as 1% (1 in 100) for CVS and 0.5% (1 in 200) for
amniocentesis should be taken into consideration.
How long does it take to obtain test results?
Results of buccal cell DNA paternity testing are usually available within 5 to
10 days after receipt by the laboratory. DNA paternity testing by CVS or
amniocentesis would take between three and four weeks before results could be
made available.
Are home DNA paternity testing kits available?
Yes. Several laboratories offer home testing kits that can be purchased over the
Internet. The kits contain all the necessary materials and instructions for
conducting a cheek cell swab test. After the DNA cheek cells are collected, the
sample is sent to the laboratory for analysis. If directions are correctly
followed, the testing technique and accuracy of a privately conducted home test
does not differ compared with a test required by court order. For court ordered
testing, however, the alleged father would need to report to a designated
paternity testing facility so that the testing can be witnessed and fingerprints
and photographs can be confirmed.
How can I locate a paternity testing facility?
The AABB (formerly known as the American Association of Blood
Banks) is an organization that provides accreditation for laboratories offering
relationship testing (including paternitiy testing). Accreditation means that
each laboratory listed has met specific standards for testing accuracy and
service. For a list of AABB accredited relationship testing facilities, please
visit AABB Accredited Relationship Testing Facilities.
Can the results of a home test be used in a court of law?
Without legal identification of the test taker and official witnessing of the
test, a home paternity test is not admissible in court.
How much does a paternity test cost?
Tests costs will vary from less than $100 for some home kits to over $500 for
the complete testing process through an accredited facility. You will need to
contact your nearest facility to get an exact price estimate.
©Copyright 1995-2012 The Cleveland Clinic Foundation. All rights reserved
index#10119
| 
