The World Leader in Private DNA Testing

The U.S. Surgeon General has set Thanksgiving Day as the “National Family History Day.” According to their website,

Over the holiday or at other times when families gather, the Surgeon General encourages Americans to talk about, and to write down, the health problems that seem to run in their family. Learning about their family’s health history may help ensure a longer, healthier future together.

With all the recent discussion on the new direct-to-consumer genetics available to find out what characteristics and disease susceptibilities individuals have inherited from their parents, the American College of Medical Genetics has issued a press release entitled, “Know the Myths and Facts about Genetic Testing.” They remind us that:

DNA tests are most often ordered and best interpreted in the context of family health history and with the support and guidance of a healthcare professional.

Dr. Michael Baird, DDC’s laboratory director, appears in several episodes of the Judge David Young Show this season.

DDC has performed DNA testing for the show since 2007, but this is the first year that they have arranged for Dr. Baird to deliver the test results over streaming video into the courtroom.

DDC is pleased to announce that it is now accepting paraffin-embedded tissue samples as a source of DNA for paternity testing. This may be very useful in cases where the alleged father or child is deceased or missing, and a medical examiner, coroner, or hospital pathologist has previously collected tissue samples and preserved them in a paraffin wax block.

Paternity questions often arise during inheritance and custody disputes, and the laboratory can use a variety of samples for DNA testing, such as blood, buccal swabs, and others—including tissues embedded in paraffin. Paraffin-embedded tissue samples may be available when an individual has been biopsied in order to diagnose or monitor a medical condition. These samples would typically be processed and stored by a hospital pathologist. Tissues may also be collected by way of an autopsy by a medical examiner or coroner’s office in cases of an unexplained and/or suspicious death. If necessary, these samples can be obtained by an individual’s next of kin or court order for the purpose of paternity testing of a deceased or otherwise missing alleged father or child.

DNA extraction from paraffin-embedded tissue samples can be challenging. Tissue type, age of the sample, storage conditions and the process used to fix the tissue prior to embedding in paraffin wax can all have an impact on the DNA. Issues faced with DNA extraction from paraffin-embedded tissues include DNA degradation and/or cross linking; however, protocols have been developed that allow for the extraction of DNA suitable for paternity and other identity testing. Dr. Melissa Kahsar, one of DDC’s assistant laboratory directors, has tested and implemented a protocol to extract DNA from tissues embedded in paraffin blocks with a moderately high rate of success. DDC is excited to add this new option to our menu of DNA testing services.

This week, two of DDC’s scientists are attending the 19th International Symposium on Human Identification in Hollywood, California.

Laboratory director Dr. Michael Baird co-hosted a pre-symposium workshop Sunday on the use of non-autosomal markers in relationship analysis. Speakers presented Y-chromosomal and X-chromosomal STR analysis in addition to mitochondrial DNA sequencing. Methods to incorporate the results of non-autosomal genetic markers into calculations for relationship were also discussed.

Assistant laboratory director Dr. Keen Wilson is presenting a poster on the use of X-STRs in complex relationship testing cases. X-STRs are DNA markers found on the X chromosome, which follow a unique inheritance pattern. Males carry only one X chromosome and therefore pass that obligate chromosome to their daughters. In a siblingship test, for example, females with the same father will inherit the father’s only X chromosome, and therefore his X chromosome markers will be present in both their profiles, giving additional information during the analysis.

This year, the topic of direct-to-consumer genetic testing has been highly discussed and debated in the media. A previous post discusses the different types of genetic testing available to consumers today. At particular issue is the actions or behavioral changes someone might make after learning about his or her health risks and predispositions via a DNA test, potentially without the advice of a doctor.

With October being breast cancer awareness month, the media’s attention has turned to DNA testing for breast cancer-related genes, BRCA1 and BRCA2. Some companies have started to market this directly to consumers, according to this MSNBC article. In reviewing the services offered to the public, the writer notes that more than 200,000 new cases of breast cancer were diagnosed in 2007, of which about 20,000 were determined to be connected to the BRCA genes. A DNA test for these genes, therefore, only applies to a small percentage of breast cancer cases. The article suggests that “only women who have a strong family history of breast cancer — two or more parents, grandparents or siblings who have developed the disease — need to talk to their doctor or a genetic counselor about the value of any form of genetic testing.”

DDC has recently added videos to its Science and Technology section. Science enthusiasts, students, and anyone interested in DNA testing can view a series of 7 short videos explaining the science of DNA testing.

Through the use of 3D animation and live footage from DDC’s laboratory, the video series explains how paternity testing works, and goes into the details of the DNA testing process, from the basic premise of DNA and heredity, to DNA sample collection and extraction, PCR, and genetic analysis.

We hope you enjoy the videos, and we welcome viewer’s comments and suggestions!

Fox News reported that Brady and Mindy Hill of Arkansas is suing a medical facility after a failed vasectomy and miscarriage. The medical staff allegedly suggested that infidelity was the reason for the pregnancy, but paternity testing confirmed that Brady was the father. The Hills sued the staff for negligence and defamation, arguing that they caused Mindy physical and emotional distress leading to the miscarriage.

According to a Medscape article, 500,000 vasectomies are performed each year in the United States. Historically, failure rates ranging from 0.3% to 8.7% have been reported for different vasectomy procedures. Men are usually recommended a course of follow-up semen analyses scheduled by their doctor to ensure that the vasectomy was effective. However, depending on the procedure used, there may still be a small risk of future pregnancy.

A DNA test can quickly resolve questions of paternity during a possible failed vasectomy. DNA samples can be taken from the parents and the baby using a simple cheek swab. A prenatal paternity test can also be performed, if needed.

If you own a mixed-breed dog, perhaps you’ve encountered the question “What kind of dog is that?” and not known the answer. DDC’s veterinary division is pleased to announce that it now offers a test to determine the breed makeup of “mutts” or mixed breed dogs.

Like DNA testing in humans, the breed makeup test uses cheek swabs as samples, which can be sent by mail to the laboratory. The test can detect up to 65 common dog breeds, and reveals the percentage of the dog’s DNA that a particular breed contributes. For example, a dog breed detected as Level 1 means that over 75% of the dog’s DNA is contributed by that breed, while a Level 5 means that the breed contributes less than 10% to the tested dog’s DNA makeup.

The test can provide valuable insight on pets’ health and behavior tendencies, based on the breeds detected.

As part of DDC’s commitment to provide the most comprehensive relationship testing in the industry, our laboratory has been investigating additional DNA markers that can be used to analyze complex relationship cases. To complement the standard set of STR markers that are routinely used in paternity testing, DDC scientists have recently been undertaking research and development on non-autosomal markers.

An autosome is a chromosome that is not a sex chromosome. In humans, most of the DNA is in the form of 46 chromosomes: 22 pairs of autosomes and the sex chromosomes X and Y. DNA markers found on the X and Y chromosomes are called non-autosomal markers. Additionally, markers on mitochondrial DNA (mtDNA), which is found outside the nucleus, comprise the third type of non-autosomal markers our scientists are studying for possible use in complex relationship testing cases.

The non-autosomal markers provide different information from the standard STR markers because of their unique inheritance patterns. Y chromosomes are passed down only from father to son; mtDNA is passed from a mother to all of her children; and a father passes the same X chromosome to all of his daughters. Therefore, non-autosomal markers can prove very useful when additional genetic information is needed to resolve siblingship, grandparentage, and genetic reconstruction cases.

In a siblingship test, for example, females with the same father will inherit the father’s only X chromosome, and therefore his X chromosome markers will be present in both their profiles. The test becomes even more powerful when the mother is tested, and her X chromosome markers can be subtracted from the siblings’ profiles.

The results of our scientists’ study on X chromosome markers and their possible use in solving complex family relationship cases will be presented to other DNA researchers during the upcoming 19th International Symposium on Human Identification. For more information about DDC’s DNA testing services, please visit our DNA Testing page.

DDC’s forensics division has worked with The Ohio Innocence Project and the Franklin County Prosecutor’s office to provide DNA testing that resulted in the release of longtime prison inmate Robert McClendon. After 18 years of imprisonment, a Franklin County, Ohio, judge ordered McClendon’s release after DNA analysis found no match between McClendon’s DNA sample and the DNA found in the submitted evidence. Based on this new evidence, McClendon walked out of the courtroom a free man on August 12.

In January, The Columbus Dispatch ran a five-part investigative series that re-examined the cases of 313 inmates who had requested DNA testing in the state of Ohio. Together with the Ohio Innocence Project, the Dispatch investigative team selected 30 cases they determined to have “legitimate claims of innocence.”

DDC offered to administer the DNA testing for these selected cases free of charge, in the interest of pursuing justice through science. The case of Robert McClendon marks the first of these cases to be resolved, with DNA testing playing a critical role in its outcome.

For more details on McClendon’s case, or to read the five-day investigative series that prompted the DNA testing, entitled “Test of Convictions,” visit the website of The Columbus Dispatch. Also read DDC’s press release to learn more about our role in the testing.