That’s right April 25th is National DNA Day. It was proclaimed by both the US Senate and the House of Representative in 2003 and while you might not have the day off you might want to stop and think about just what DNA has done for us.
DNA Day is a remembrance of the day in 1953 when a gound breaking article on the structure of DNA was published as well as the the day that the Human Genome Project was completed in 2003.
DNA has made big changes in our lives whether we know it or not. So this April take some time to think about DNA and some of it’s many uses:
1. In archeology DNA helps record genetic information of life on earth many centuries ago. This creates a data base that can be used to learn more about our planets past.
2. Genetic testing is used to determine the paternity or maternity of a child.
3. DNA testing can be used to help create a family tree or genealogical chart. Through genetic data bases one can trace lost relatives or find ancestors. Using both the Y chromosome and Mitochondrial DNA people can use DNA testing to establish ancestral lines (both remain unchanged for generations).
4. Prenatal genetic tests can help doctors determine whether or not the unborn fetus will have certain health problems.
5. DNA tests are also used to help solve murders and other crimes. In recent years many unsolved mysteries have been solved due to new ways of analysis as well as clearing many people found guilty of crimes that the did not commit.
6. DNA testing finds great use in the health field as DNA sometimes is the cause of rare medical conditions or heritable diseases.
7. Genetic testing is used in healths checks. For example it can be used to help determine the presence of viruses or cells that have mutated (causing cancer).
8. DNA tests are often used to reunite lost siblings or families or identify remains of the unknown. The genetics of a person leaves an indelible mark and this is used by police, military and authorities as well as individuals to confirm relationships.
9. DNA tests on new species or on material from outer space help scientists and researchers determine the origins of a species and where they stand with reference to known living forms.
Most people don’t realize that there are many different types of twins in the world. Not only can you be identical or fraternal twins but you might be one of any number of other type. Below are some of the most common other types of twin.
1. Conjoined Twins are monozygotic multiples that do not fully separate from each other due to the incomplete division of the fertilized ovum. The individuals will be connected at certain points of the body, and may share tissue, organs or limbs.
2. Twins Conceived Separately or Superfetation Twins occurs when an egg is released while a woman is already pregnant, resulting in twins that are conceived at different times.
3. Twins with Different Fathers or Heteropaternal Superfecundation occurs when fraternal (dizygotic) twins which are the product of multiple eggs being released in a single cycle are fertilized by sperm from separate incidences of sexual intercourse. In a case where a woman has sex with different partners, the twins could have different fathers and the appropriate term is heteropaternal superfecundation.
4. “Half Identical” Twins or Polar Body Twins is a theory at this time. There are two types of twins, right? Dizygotic (fraternal) twins result when two eggs are fertilized. Monozygotic (identical) twins come from a single fertilized egg that splits. But what if the egg splits and then each half meets a sperm? That’s the proposed theory for polar body or “half-identical” twins, twins who are very much alike but aren’t a 100% DNA match. Although it seems to be a reasonable theory, there is no definitive test to confirm polar body twinning.
5. Boy/Girl Identical (Monozygotic) Twins occurs when there is a genetic mutation in male twins where one twin loses an Y chromosome and develops as a female. The female twin would be afflicted with Turner’s Syndrome, characterized by short stature and lack of ovarian development. Of course, another explanation for gender differences in identical twins is an identical twin who undergoes a sex change operation.
6. Mirror Image Twins are monozygotic, twins that form from a single fertilized egg. When the split occurs late – more than a week after conception – the twins can develop reverse asymmetric features. This term is not really a type of twin, just an way to describe their physical features. For example, they may be right- and left-handed, have birthmarks on opposite sides of their body, or have hair whorls that swirl in opposite directions. In theory, if the twins faced each other, they would appear to be exact reflections of each other. About 25% of identical twins are mirror image twins.
7. Parasitic Twins is a type of conjoined twins that develops asymmetrically, with a smaller, less formed twin dependent on the stronger, larger twin. A variation of parasitic twinning is fetus in fetu, where an abnormally formed mass of cells grows inside the body of its monozygotic twin. It survives during pregnancy, and even occasionally after birth, by tapping directly into the blood supply of the host twin.
8. Semi-Identical Twins is a type of twinning identified as identical on the mother’s side but sharing only half their father’s genes, the rare twins developed when two sperm fertilized a single egg, which then split.
9. Twins with Different Birthdays the most common explanation is a labor and delivery that begins before midnight and ends on the following day. If that day happens at the end of the month, or even the end of a year, the two babies can have birthdays in different months and even different years. Sometimes a pregnancy is prolonged to provide each baby with an optimal chance for survival. If preterm labor forces the delivery of one baby, doctors can successfully control the labor and delay delivery to give the other baby more time in the womb. Twins and higher multiples have been born days and even weeks apart.
10. Twins of Different Races can be caused by heteropaternal superfecundation. There are cases of fraternal (dizygotic) twins with differing racial characteristics. In one case, the differentiation was due to a lab mix-up during an in-vitro procedure. However, there is a case where two bi-racial parents conceived fraternal (dizygotic) twin girl twins, experts explain that the girls inherited different genetic characteristics from their mixed race parents. One is fair-haired and light skinned, while the other has dark hair, eyes and skin.
Back in the 1700s, the best way to determine who a persons father was, was by taking a good hard look at the child, followed by a good hard look at the father. If there were enough coincidences then maybe a relationship could be possible. by the 1800s, it was discovered that eye color could be a paternity identifier. With recent DNA advances we have learned that the eye color theory is flawed. We now know that eye colour is determined by at least six different alleles, or genetic markers. Fortunately paternity testing has become a lot easier and much more affordable over the past few years due to advances in DNA science.
Although an estimated 200,000 DNA tests are conducted each year by states needing to determine child-support and welfare issues, not as many people are willing to conduct their own at-home paternity test because they don’t realize the simplicity and convenience of an at-home paternity test.
How does home DNA testing work?
Paternity testing requires a painless sample from both the child and possible father. Even without a sample from the mother, DNA paternity test results are up to 99.9% accurate. Most companies provide testing material which they will mail directly to you so that you can provide the samples.
Because of advances in DNA testing it is no longer necessary to draw blood. Buccal (mouth) swabs are the standard. These swabs have the same genetic information that is carried in blood but none of the hazards. By gently massaging the inside of the child’s mouth, cheek cells are collected. These cells are then sent to the lab for testing. Labs analyze up to sixteen genetic markers of the child and match them against the markers of the alleged father. Because each of us receives half our genetic markers from each parent, the results of DNA paternity testing are still accurate without the DNA information of the mother but a really good test will include the mother this helps insure that there is no chance of a false positive.
What else can a DNA test do?
DNA test kits can also be used to analyze sibling relationships, establish cousin or grandparent relationships, determine twin zygosity (i.e. whether twins are fraternal or identical), identify ancestral origin, verify Native American decent, assure parents they left the hospital with the right baby, and most important, provide legal evidence – be prepared to pay a bit more for legal tests. Legal tests can be used to settle adoption issues, settle child-support disputes, and provide information for immigration files. Legal tests can not be preformed using a home test kit.
How to choose a DNA laboratory
Enjoy piece of mind. Be confident that the questions you have can be answered and that DNA testing is safe easy and stress-free.
By Alex Blake
DNA testing is done for a variety of reasons. DNA evidence can link an alleged criminal to a crime scene. DNA paternity and maternity testing can identify a child’s father or mother. DNA relationship testing can determine if two individuals are from the same family. DNA ancestry testing can determine ethnic origins and genealogical roots.
How DNA testing is done depends on the what kind of results are desired and on what types of samples are available. DNA fingerprinting (or profiling as it’s also known) is the process of analyzing and comparing two different DNA samples. Only identical twins have the exact same DNA sequence, everyone else’s DNA is unique. This makes DNA the perfect way to link individuals to each other or to locations where they have been.
The entire DNA chain is incredibly long, much to long to examine all of it in one test. Human DNA is made up of about 3.3 billion pairs. The differences between DNA samples occur only in small segments of the DNA–the rest of the DNA is pretty much the same. DNA testing focuses on those segments that are known to differ from person to person.
As DNA testing has evolved over time, the testing methods have become more precise and are able to work with much smaller DNA samples. Early DNA testing was done using dime-size drops of blood. Today’s tests can extract DNA from a drinking container. The DNA is extracted from whatever sample is provided (some times there is not enough DNA to provide for testing). DNA must be isolated and purified before it can be compared. In essence, it has to be “unlocked” from the cell in which it exists. The cell walls are usually dissolved with a detergent. Proteins in the cell are digested by enzymes. After this process, the DNA is purified, concentrated, and then tested.
DNA testing is done most often today by using a process called “short tandem repeats,” or STR. Human DNA has several regions of repeated sequences. These regions are found in the same place on the DNA chain, but the repeated sequences are different for each individual. The “short” tandem repeats (repeated sequences of two to five base pairs in length) have been proven to provide excellent DNA profiling results. STR is highly accurate–the chance of misidentification being one in several billion.
By Kevin Camilleri
DNA paternity testing of related potential fathers is fairly common, although in these types of paternity cases it is more difficult to prove paternity beyond any shadow of a doubt. It is always best to included both potential father in this type of test.
While positive DNA tests can be accepted as positive evidence of paternity in the most cases due the statistical improbability of potential fathers having the same DNA profiles, if the possible fathers are related they are more likely to have similar DNA profiles. It isn’t uncommon for brothers to be involved in a parentage dispute, or even for the mother to have a DNA test carried out privately to determine which is the father of her child.
The Legal Aspects
Where DNA paternity testing is to be used in evidence, courts will generally insist on a legal paternity test where the collection of the sampling is carried out by an authorized professional and the identity of the subject legally determined though an ID check and photo documentation. Home DNA testing, or DNA tests on samples presented by the subject, are not admissible as evidence. The probability of paternity accepted as definitive proof varies from state to state, although most states require a probability of 99%.
Such probability is determined largely by the DNA, and the manner the test is preformed. A good DNA test looks at 16 genetic markers, it would run all tests twice independent of each other, and should guarantee resutls of 99.9+%. It also depends on whether the sample of the Mother is included in the testing or not, as this will help to obtain a much higher level of probability.
Common DNA between Family Members
DNA tests on related potential fathers are no different from those carried out on any other subject: it is the results that could potentially create problems. Take the case of first cousins: they share 12.5% of their DNA and so it will be more difficult to prove parentage. This sharing of DNA increases to 25% for uncles, nephews and half-brothers, and to 50% for sons, fathers and brothers of the person being tested.
DNA paternity testing on different members of the same family is not an uncommon situation, and can occur for a number of reasons, including:
a) Pregnancies arising from consensual and non-consensual relationships with related men.
b) Two family members each claiming parentage, whether or not the mother is claiming one or neither to be the father.
c) A brother desiring confirmation that he is the parent.
d) The mother, or potential mother, having a private test to assure herself as to who is the father.
e) A grown child confirming parentage, particularly where an inheritance could be involved.
There are others, but these are common reasons for legal and home DNA tests being carried out where potential fathers are related. Standard DNA paternity testing statistics are based upon unrelated members of the public, and unless the laboratory carrying out the DNA testing has been informed of the relationship, the test results could be misinterpreted. Most reputable DNA testing companies will recommend that you preform a paternity test with each of the potential fathers to verify which would be a closer match to the child.
The Case of Identical Twins
Nevertheless, it is possible to test additional DNA markers if any of the above relationships are known, but not in one specific case. This is the case of identical twins. Fraternal twins occur when two eggs are fertilized by two sperm, and are no more alike genetically than were they siblings born years apart. Identical twins, however, are formed when one egg is fertilized by one sperm and then splits into two halves within the first 14 days for no known reason.
These twins share an identical DNA their DNA profiles would be indistinguishable from one another. There is no test that can determine which is the biological father of a child. Unless one is excluded for some reason, either could be the father and that is all that DNA testing can prove. The court would have to disregard DNA results and use other means to determine paternity.
Old-fashioned policing, therefore, still has a part to play where the related potential fathers are identical twins. Apart from this specific case, DNA paternity tests are not entirely foolproof since they rely on probability, but are virtually conclusive where you simply want confirmation of paternity. In such a case, a likelihood of 1 in a 1000 is a virtual certainty and where confirmation is required between a limited number of candidates, a 99.9% DNA genetic testing result is legal confirmation.
A new study failed to provide answers after pursuing a genetic explanation for why one identical twin developed multiple sclerosis while the other stayed healthy. Researchers created complete genetic blueprints for a pair of identical twins, looking for differences that might explain why one developed multiple sclerosis and the other did not. According to researchers there were no traces of a discrepancy in the twins’ DNA. Scientists found no smoking gun when they compared amount of gene activity between the twin with multiple sclerosis and the twin without. The results appear in a study published on April 29 in Nature.
According to Stephen Kingsmore, a geneticist at the National Center for Genome Resources in Santa Fe, N.M., and leader of the new study, “We looked under a lot of rocks and we found no differences that we could replicate.” Kingsmore went on to say that the findings “points to some novel environmental trigger that must be very important to the disease. We don’t know what it is.”
This study was small; it examines only three pairs of identical twins and one type of immune cell known to be involved in multiple sclerosis. A telling difference between sickness and health might be found in other types of cells, says Esteban Ballestar of the Bellvitge Biomedical Research Institute in Barcelona, Spain. Ballestar went on to say, “They are closing a door here, but I think, perhaps, the door should be open.” Multiple sclerosis is a disease where the immune system attacks and damages the myelin sheath that helps speed electrical communication between nerves, this is the equivalent of scraping the coating away from an electrical wire. The damage results in pain and symptoms such as loss of coordination and vision.
In the study, Kingsmore and his colleagues determined the entire genetic makeup of the immune cells called T cells from the female twin who had developed multiple sclerosis at age 30 and from her twin who had remained healthy. It was important that the twins were now old enough that the healthy one is not likely to develop the disease.
Identical twins share the same genetic makeup (it is believed that they have identical DNA), and the researchers confirmed that both women carried variants of genes already known to increase the risk of getting multiple sclerosis. Scientists had thought that maybe the sick twin had developed an additional mutation in her DNA that finally triggered the disease. But the team found no such mutations.
I just came across an article distributed by the Slate discussing the above topic. This brought my thinking to the use of DNA and the idea of anonymity in general.
DNA testing makes them easy to trace
By Rachel Lehmann-Haupt Last Updated Monday, March 1, 2010, at 9:36 AM ET
When Donor 3066 signed up with the California Cryobank, he offered some basic information about himself on a piece of paper: that he had a BA in theater; that his mother was a nurse and his father was in the Baseball Hall of Fame; that his birthday was Sept. 18, 1968. He made it clear that he didn’t want to be found by signing a waiver of anonymity…
Donor 3066 was being sought out by Michelle Jorgenson, a 39-year-old waitress from Sacramento, Calif., whose daughter, Cheyenne, was born in 1998. When her daughter turned 5, Jorgenson joined the Donor Sibling Registry and began searching for other mothers and donor offspring who used Donor 3066. She was concerned because her daughter was sensitive to sounds and walked on her toes, and she wanted to know if other half-siblings were displaying similar behavior. Through the registry, she met a number of other mothers and half-siblings. She discovered that two had autism and two others showed similar signs of sensory disorder…
Jorgenson began her search by approaching a mother in her group with a son named Joshua and suggested he do a cheek swab so she could explore his paternal roots through a Y chromosome test. The mother agreed. Through the test, Michelle learned about some of Joshua’s genetic markers. A few weeks of searching on the Family Tree DNA Web site using these markers led to two families with matching DNA. Through one of the families, she met a woman who mentioned that she found the obit of a relative who was a former baseball manager, and three children were listed. Michelle suspected that this might be her donor’s father, so she looked up the phone number of his listed son. When Michelle called the number, the deceased man’s son answered the phone. She began to ask him questions: Was your father in the Baseball Hall of Fame? Were you born in Illinois? Did you ever donate sperm? When the man said yes, she asked him if his birthday was Sept. 18, 1968. When he answered yes, she burst into tears. “You’re the biological father of my daughter,” she said. He was shocked but agreed to talk to Cheyenne on the phone—and eventually allowed the two to come visit him in Los Angeles.
Although in this case there appears to be a happy out come for all parties this is not always the case. What about the request for privacy that Donor’s sign up for when they choose to remain anonymous? Is that even something that clinic should offer since there is no guarantee that the donor can’t be found? What are the options for men who do become donors? There are many questions that are raised in this article and very few answers, partly because technology is growing at such a fast rate and party because it appears in the article many clinics are ignoring this issue of privacy. Let us know what you think about this issue.
Paternity for many is a tough issue, both emotionally and legally. Paternity is assigned to men and boys in a few ways. The first is by marriage. Men are automatically assumed to be the father if they are married to the mother or in many states if they attempted to marry the mother and did not do so in a legal manner. The second is by voluntary acknowledgment. This is a typically a form that is signed in the hospital prior to the release of the mother and child. The third is by court judgment.
Most if not all states have a law that looks something like this:
(1) A man is presumed to be the father of a child if:
(a) He and the mother of the child are married to each other and the child is born during the marriage;
(b) He and the mother of the child were married to each other and the child is born within three hundred days after the marriage is terminated by death, annulment, dissolution of marriage, legal separation, or declaration of invalidity;
(c) Before the birth of the child, he and the mother of the child married each other in apparent compliance with law, even if the attempted marriage is, or could be, declared invalid and the child is born during the invalid marriage or within three hundred days after its termination by death, annulment, dissolution of marriage, legal separation, or declaration of invalidity; or
(d) After the birth of the child, he and the mother of the child have married each other in apparent compliance with law, whether or not the marriage is, or could be declared invalid, and he voluntarily asserted his paternity of the child, and:
(i) The assertion is in a record filed with the state registrar of vital statistics;
(ii) Agreed to be and is named as the child’s father on the child’s birth certificate; or
(iii) Promised in a record to support the child as his own.
(RCW 26.26.116 Presumption of paternity in context of marriage. on leg.wa.gov)
While this law might seem reasonable to many it does not take into account that it is estimated that 40% of wives will have an affair at some point in their marriage (www.caughthercheating.com) What if that child is not the husbands?
The second way is for the father and mother to sign Voluntary Acknowledgment of Paternity form at the hospital when you have your baby. The hospital staff will give you this form and help you complete it. When you and the child’s father sign the Voluntary Acknowledgment of Paternity form, the father’s name will be placed on the birth certificate.
If you and the baby’s father are unable to sign the Voluntary Acknowledgment of Paternity form at the hospital, you may complete it at home. Your signature must be witnessed by someone over 18 years old, and by a person not named on the voluntary acknowledgment.
You don’t have to be the biological father to sign this form there is no proof required you are stating you are the father and will be responsible the moment you sign this from. Most states but not all have laws that allow you to challenge paternity that is assigned based on the Voluntary Acknowledgment of Paternity. They typically have a set time period with in which you can contest your paternity.
The third way is to have paternity assigned to you by a court. This can happen if the alleged father does not responded to a woman’s claim for paternity or if the Judge or Jury feels that it is in the best interest of the child. For example a section of Missouri’s bill requires courts to balance the best interests of the child and the hardships of the man who is contesting paternity regardless of a DNA test proving that he is not the father.
“James McClendon knows he’s not the biological father of his ex-girlfriend’s 16-year-old son. He’s got a DNA test to prove it. But his wages are trimmed each month to pay thousands in child support debt. McClendon, who lives in St. Louis, has been fighting a 10-year legal battle to overturn a paternity ruling that says he’s the child’s father. Between legal bills, supporting his three biological children and several failed jobs, he’s built up $25,000 in child support debt.” (States move to allow DNA paternity challenges, By LEE LOGAN The Associated Press www.kansascity.com)
Stories like this are not all that uncommon unfortunately and have been a leading reason why in over 30 states laws are being or have been enacted to allow men to challenge paternity with a DNA test. A major force lobbying for changes to paternity laws is Carnell Smith, an engineer in Atlanta. Smith successfully lobbied for a Georgia law that allows men to challenge paternity at any time. Smith who calls himself a victim of “paternity fraud,” used this same law to erase his own paternity ruling in 2003. Carnell Smith has formed a national organization lobbing for similar laws in other states.
56 Years ago, two Oregon women, Kay Rene (Reed) Qualls and DeeAnn (Angell) Shafer, were born at Heppner’s Pioneer Memorial Hospital. While both girls were being bathed they were accidentally switched and returned to the wrong mothers. The mistake was not discovered until the summer of 2008, when a former neighbor of the Angell family, and a friend of the Reed family, contacted Kay’s older brother, Bobby.
The 86 year old woman told Bobby that she “needed to get something offer her chest”. She claimed Marjorie Angell, DeeAnn’s mom, had insisted she’d come home with the wrong baby – nurses had taken her baby and the Reed baby, both bald and weighing about 6 pounds, and bathed them together, when they returned with the babies, they’d been switched.
Both families compared stories and learned that rumors of the switch had been talked about for years. They decided to preform a sibling-ship test to determine the truth as both sets of parents were deceased. DeeAnn and Kay tested with two of Kay’s purported siblings and discovered that they had, in fact, been switched at birth!
It should comfort some to know that, while mistakes can happen, it is highly unlikely that this type of oversight could be made at a hospital in this day and age, as there are many precautions taken. Furthermore, should a mother have concerns, she is now able to do purchase and perform a maternity DNA test.
For the Full story:
A Texas mother of twins discovers that they have two separate fathers. The mother, Mia Washington, cheated on her partner, James Harrison, with another man. One of her eggs was fertilized by James Harrison’s sperm and the second egg was fertilized by the other man, thereby causing fraternal twins with two separate fathers. (Identical twins occur when a single egg is fertilized by a single sperm and then, when it is a zygote, splits into two which creates a natural clone of it’s self. A DNA test to determine if twins are fraternal or identical is called a Twin Zygosity Test.)
In order for it this to occur, “The infidelity would have had to occur within a 24 to 48 hour period,” says Dr. Joseph Finkelstein, a Manhattan obstetrician and gynecologist. “Once the egg is released and is fertilized, the system shuts down, so although it technically could happen, it would have to happen in two days or less.” The likelihood of having twins without any medical intervention such as the use of fertility drugs is about 1 in 100, Finkelstein says.
“Texas woman gives birth to twins – from different fathers”