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Home DNA Testing

News and insights in the world of DNA and genetics for paternity, immigration and forensics

Archive for May, 2009 Monthly Archives

Julia Pastrana, the most famous “Bearded Lady”, was a Mexican-born woman who exhibited herself in 19th-century Europe as part of a traveling circus, dancing and singing in clothes that showed off her hairy visage and limbs. At the time, she was considered a freak and no one knew why she was cursed with this hairy condition. It all comes down to DNA. As it turns out, Julia had Hypertrichosis Terminalis, or CGHT.

CGHT is a condition where excessive hair grows over and above the normal amount for the age, sex and race of the individual. It can develop all over the body or can be isolated to small patches. CGHT is an extremely rare but highly inheritable disorder.

Geneticist, Xue Zhang, of the Peking Union Medical College in Beijing, has set out to discover a cure, or at least a cause for this disease and has scoured China for cases he can research. His team found three affected families, including 16 afflicted members, who were willing to participate in a study.

Xue Zhang, and his research team, first conducted a genome-wide linkage scan in a large four-generation family which showed a genetic locus (location) for CGHT. Afterward, they conduced further studies on the genetic markers from the same chromosome region. (This confirmed genetic mapping previously performed.) They found that in every family a microdeletion (the loss of a tiny piece of a chromosome), within the critical region of the locus, was present in all affected individuals but was not present in unaffected family members. This research successfully and conclusively identifies CGHT as a genomic disorder. Now lets hope he can find a cure!

Click here to read the full article

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”
http://www.nydailynews.com/lifestyle/health/2009/05/18/2009-05-18_texas_woman.html#ixzz0G5OLyDcv&A

The earth environment that surrounds us on a day to day basis has been proven to be quite polluted, especially in certain areas of the world or locations such as offices or workplaces. The heavy metals and toxins that we can be exposed to, such as mercury and asbestos, have been known to cause diseases in animals and humans. Research is ongoing regarding the genetic affects that this pollution can have on us.

A recent study focused on this issue and the rate at which pollution can damage or change DNA. It was performed by Dr. Andrea Baccarelli and a team of scientists from the Center of Molecular and Genetic Epidemiology  (Department of Environmental and Occupational Health University of Milan, Italy). This study used the DNA of 63 healthy foundry workers in Italy. Blood DNA samples were collected on the morning of the first day of the work week and again after three days of work. The study compared the samples taken on the different days and proved that the environmental pollution absorbed by the workers caused some genes to become reprogrammed, which in turn affects both the development and the outcome of cancers and other diseases, and that significant changes had occurred in four genes associated with tumor suppression in such a short period of time.

According to Dr. Baccarelli, “The changes were detectable after only three days of exposure to particulate matter, indicating that environmental factors need little time to cause gene reprogramming which is potentially associated with disease outcomes. As several of the effects of particulate matter in foundries are similar to those found after exposure to ambient air pollution, our results open new hypotheses about how air pollutants modify human health.”

For more information see:

http://www.thoracic.org/search.cfm?q=Andrea+Baccarelli&x=0&y=0

http://news.nationalgeographic.com/news/2009/05/090517-pollution-changes-dna.html

There are currently only two reliable methods of prenatal, prebirth DNA Paternity or genetic testing – Amniocentesis and Chorionic Villus Sampling (CVS).  Both are also more typically used to detect birth defects with the fetus. There is generally quite a bit of confusion about both methods of testing. Please allow us to explain:

An AMNIOCENTESIS is a procedure which removes a small sample of amniotic fluid that surrounds a fetus. Amniotic fluid contains fetal cells and waste products which are discharged from the fetus. These cells can provide genetic, or DNA, information just like blood or a cheek swab.  The Amniocentesis procedure is performed by an OBGYN  by inserting a needle through the mother’s abdomen and into the uterus. Approximately 2 Tbsp of amniotic fluid is drawn out, which is then shipped via overnight mail on blue ice and tested in the laboratory. An Amniocentesis is performed, on average, between weeks 14 and 24 of the pregnancy.

The fluid that is obtained through the draw can be used to test the parentage of the child, or in determining the sex of the child,  in addition to screening for over 100 types of disease inherited from the family.  Examples of these diseases are Down Syndrome, Cystic Fibrosis, Sickle Cell disease, and Huntington’s disease.  While this procedure is routinely performed and can be safe, some risks are involved and the pregnancy can be endangered. This is why most physicians do not want to perform the procedure unless it is medically necessary. (A DNA Paternity test is not deemed medically necessary.)

RISKS: During an Amniocentesis there is the possibility of injury to the mother or the fetus from the needle.  The most common injury occurs from puncturing the placenta, but it is also possible that an infection can occur due to the introduction of bacteria into the amniotic fluid, as well as cramping, bleeding and leakage of Amniotic fluid.  This procedure also carries some risk of causing a miscarriage and when it is performed prior to 15 weeks. Studies have also shown an increased risk that the fetus will develop clubfoot from the procedure.  Unfortunately, all pregnancies have a risk for miscarriage, whether a test was performed or not. In the second trimester (when an amniocentesis is typically performed), the normal risk for miscarriage is between 2-3%. The risk for miscarriage is increased slightly with amniocentesis and the risk of amniocentesis-related miscarriage is 1 in 250 to 1 in 300.

CHORIONIC VILLUS SAMPLING, or CVS for short, is a test that can find certain problems with a fetus. CVS is performed late in the first trimester, most often between the 10th and 14th week.

CVS samples can be collected in one of two ways -  either by putting a thin flexible tube (catheter) through the vagina and cervix directly into the placenta (transcervical CVS),  or by inserting a long needle through the belly into the placenta (transabdominal CVS), which is similar to the amniocentesis procedure. The method that is used is dependent upon the position of the placenta and uterus. This will be determined the day of the procedure during the ultrasound examination. A thorough ultrasound examination is performed prior to and during the procedure.

The type of sample that is taken during a CVS procedure are the Chorionic Villus Cells. Chorionic Villi are similar to tiny fingers and grow inside the placenta. The genetic material inside these cells are the same as those found in the fetus’s cells.

The reasons for having a CVS performed are the same as those for an Amniocentesis -  to determine health of the fetus and parentage, if necessary.

RISKS: Just like the Amnio, there are some risks involved with the CVS procedure.  They include infection of the uterus, cramping, spotting, leakage and miscarriage. While miscarriages may occur following CVS, many can be unrelated to the CVS procedure. Studies in the United States and in Europe now suggest that the risk for CVS-related miscarriage is between 1/100 – 1/200.

While both tests offer the possibility of grave risks, the benefits can be educational or rewarding. The knowledge about your baby and it’s health can be good news, if there were concerns, or will have a different outcome which will influence your preparation for a new family member.  You might need to make special arrangements for birthing or for the child’s life and care.

When prebirth Paternity DNA Testing is being considered by the mother, her OBGYN must be consulted. The physician will be the one to approve and perform the test and therefore, the mother must begin with a visit to her doctor. As stated above, in most cases, an OBGYN will not want to perform either of these procedures if it is just for a Paternity Test, which is not medically necessary, as the risks can be too great. Some doctors have even told their patients that this kind of test is not even possible. This is not true.

If the mother is already planning on having one of  these procedures performed (which should be covered by insurance ) the doctors office will send the samples to a genetics lab for which ever test is needed. That lab can then grow more cells and send them along to a DNA Paternity Testing lab.  Mother will usually be granted a prebirth procedure if she has an abnormal ultrasound, has a family history of certain birth defects, has previously had a child or pregnancy with a birth defect, or will be 35 or older at the time of delivery.

If the mother is not planning of having one of the procedures, and her doctor still approves the procedure, she will most likely have to pay the OBGYN thousands of dollars for the procedure, on top of the DNA testing fee and shipping.

In all cases, a prebirth, prenatal DNA Paternity Test begins with a consult at the OBGYN, for methods, risks, approval or denial. DNA Testing is then performed when the mother and possible father have their samples collected, typically via cheek swab, and sent to the Paternity Testing Lab.

Sources:

 

http://www.webmd.com/baby/guide/amniocentesis

http://www.webmd.com/baby/guide/chorionic-villus-sampling

http://www.reproductivegenetics.com

While most people assume that the mother will be awarded automatic custody of a child, this is only holds true in certain cases – for instance, when the biological father has not been determined and the mother is fit to parent.   However, in most cases, the truth is that whether the parents are married or not, they both have the same right to be awarded custody.  Most courts do still tend to favor the mother for certain reasons, but when the child is between infancy and about 9 years of age there is still a valid case for awarding the father full or partial custody.

Fathers still have important rights they need to be aware of:  First, it is very important to have the child legally declared to be your child, by DNA Testing, birth certificates, or other methods.  Second, all biological fathers are entitled to reasonable rights of visitation and contact with the child, including holidays, school events, report cards, and extra curricular activities and visits to doctors and dentists.  Lastly, fathers have the right to have child support set a a reasonable amount based on their financial situation.  All states have laws regarding child support, including how to calculate what your child support dollar amount should be.

Any parent can lose custody if they are found unfit due to drug or alcohol dependency, neglect/abuse of the child, or if they fail to maintain a consistent home life for the child.  Historically, one of the many arguments for granting a mother primary custody was their constant presence in the the home.  This is no longer a valid reason because most women today now work outside of the home and are not the full time care givers.

Today, all parents have a basic right to be awarded full or partial custody. However, certain individuals will jeopardize that right should it be proven they are unfit to parent.  Each case is unique and should be evaluated on an individual basis. In some states, this judgment is made by a jury and in other states by a Judge.

For more information on State Laws, see: http://www.divorcenet.com/states