by Dr. Hsien-Hsien Lei
Posted February 20, 2008 in DNA in General
Identical (monozygotic) twins Raymon and Richard Miller had better watch out. The two were embroiled in a paternity suit that alleged both had slept with the same woman on the same day and nobody knew which brother had impregnated her. In May 2007, the judge decided that Raymon is the legal father of the child who was subsequently born although child support was split between the two brothers.
Standard paternity testing examines 16 DNA markers which is enough to make them over 99.99% accurate. In the case of the State of Missouri and Holly Marie Adams vs. Raymon and Richard Miller, the paternity test showed that the two brothers both had a 99.999% probability of being the father. There is currently no commercially available test that can determine which of the twin brothers passed his DNA to the child even though there are ways in which the genomes of identical twins differ.
Epigenomic chemical modifications. Researchers at Ohio State University found epigenetic changes in twins’ genomes that increased as pairs of twins aged. One of the main epigenetic processes that occurs to our DNA is methylation which can be caused by environmental exposures, such as diet and physical activity. Methylation can lead to differences in gene expression and as we age, the amount of DNA methylation increases. So, it’s expected that identical twins will grow less and less similar in their patterns of DNA methylation and gene expression as their lives progress especially if their lifestyle habits and surroundings differ greatly.
DNA copy-number-variation profiles. Another way in which the genomes of identical twins may differ is in copy number variation (CNV) that appears as segments of DNA that are missing, occur in multiple copies, or have flipped orientation in the genome. Identical (monozygotic) twins have been found to have different CNVs which could explain why even identical twins are not truly identical in appearance or other physical characteristics despite similar environmental exposures. For example, one twin sometimes develops a disease while the other does not. (HT: DNA Direct Talk)
What does this mean for Raymon and Richard Miller? DNA methylation patterns and copy number variations can be definitive in a paternity case if differences between the brothers are identified. Then, by comparing the same genomic regions in the child, it may be possible to see who the s/he more closely resembles genetically keeping in mind that the child is also accumulating his/her own DNA methylation and CNVs. While this type of genetic analysis isn’t currently available, it will most likely be available in the child’s lifetime. I would suggest that the Millers’ love child or his/her guardian store DNA from Raymon and Richard Miller for future analysis.
Update:: John Hawks has more.
Photo credit: Wellcome Images under Creative Commons.
DNA Video: Twin DNA Differences...
Twin DNA Foil Investigators Again...
Eye on DNA Headlines for 11 April 2008...
DNA Isn’t the Answer to Everything...
DNA Quote of the Day: Hillary Rodham Clinton...
Which came first? The genes or the divorce?...
DNA Quote: Dr. Svante Paabo...
Sorry, the comment form is closed at this time.
Search Eye on DNA
- Genetic Genealogy on Faces of America
- DNA Network Tweet Cloud
- Genetics = Real Science
- Larry David’s DNA Test
- Lopez Tonight First Late-Night Show to Offer DNA Testing
- American Genes Don’t Exist
- Knowledge about Genetic Risk is Power or is it Fear?
- Murderer Gets Reduced Sentence Because His Genes Made Him Do It
- Video: Knome’s Ari Kiirikki Speaks with Medgadget
- DNA Toys: Ben 10 and Digimon Digivice
- 100 Facts About DNA
- Salaries for Jobs in Genetics
- Fetal Gender DNA Tests Answer Common Pregnancy Question...Or Not
- How To Determine Paternity Without A DNA Test
- What does DNA mean to you?
- Eye on DNA Interview: Dr. Tzung-Fu Hsieh of RedTracer DNA Test for the Red Hair Gene, MC1R
- Books About DNA: The Crime of Reason by Robert B. Laughlin
- Genetically Modified Organisms Bring in the Cash
- Navigenics Introduces Physician Portal and Annual Insight Service
- People Who’ve Had Their Genomes Sequenced
09/29/2009 07:03 am
- Larry David’s DNA Test
11/17/2009 02:52 am
- 23andMe DNA Tests for $399, Down From $999
09/10/2008 04:33 am
- Crazy Genetic Marketing Ideas
07/05/2008 09:14 pm
- Parenting Children Using Genetic Tests
05/18/2009 02:09 am
- Business of DNA
- DNA @ Google Answers
- DNA and Disease
- DNA and Genealogy
- DNA and the Law
- DNA Around the World
- DNA Fun
- DNA in General
- DNA Inventions and Gadgets
- DNA Lab Talk
- DNA Podcasts and Videos
- DNA Quotes and Excerpts
- DNA Testing
- Gene Therapy
- Genetic Engineering
- Genetically Modified Foods and Organisms
- Jobs Involving DNA
- Personalities with DNA
- Polls About DNA
- January 2010
- November 2009
- October 2009
- September 2009
- August 2009
- July 2009
- June 2009
- March 2009
- February 2009
- January 2009
- December 2008
- November 2008
- October 2008
- September 2008
- August 2008
- July 2008
- June 2008
- May 2008
- April 2008
- March 2008
- February 2008
- January 2008
- December 2007
- November 2007
- October 2007
- September 2007
- August 2007
- July 2007
- June 2007
- May 2007
- April 2007
- The Rest of the Story: Tobacco News Analysis and Commentary
- The Minnesota Gene Pool
- Ideas for Women
- The Tree of Life
- Six Impossible Things Before Breakfast
- Genome Technology Online