What are the chances that Megan Smolenyak would meet and marry a man with the surname Smolenyak without being at least distantly related to him? What if the two surname lines came from the same area of the world? I’m sure that everyone who has heard of Megan has wondered how she came by the double last name.
Megan writes “Did I Marry My Cousin” at Megan’s Roots World to introduce a new segment at Roots Television about how she used genetic genealogy to analyze the question. The segment is available here. I highly recommend stopping by to learn more about this particular use of genetic genealogy, especially since I’m not going to give you the answer!
As I was reading through the GENEALOGY-DNA list from Rootsweb this morning, I came across a great question about the frequency of mutation of mitochondrial DNA (mtDNA).
The listmember asks “I am wondering if anyone would know the odds of having a mutation between my brother and me in our mtDNA. Marker 16163 is G for one of us and A for the other…” This is a great question, and one that I’ve been asked as well.
In response, Ann Turner writes “The mutation rate hasn’t been studied in the detail I’d like to see. The largest study for the hypervariable regions was based on deep-rooting pedigrees from Iceland. They found 3 mutations out of 705 transmission events.”
The study, available here (pdf, HT: Ann Turner) was conducted through deCODE Genetics and Oxford University. They used 26 Icelandic ancestral trees to identify maternally-related individuals, and sequenced 272 mtDNA control regions representing a total of 705 transmission events. The researchers found a total of three mutations, resulting in a mutation rate of 0.0043 per generation, or 0.32/site/1 million years. A previous study (Parsons et al., 15 Nature Genetics 363 1997) found a total of 10 mutations in 327 transmission events for a frequency of 2.5/site/1 million years, and yet another study found 2 mutations in 81 transmissions for a rate of 0.75/site/1 million years (Howell et al., 59 Am J Hum Genet 501). The huge differences in these numbers suggests that much more research needs to be done, probably with a much larger dataset. If I had unlimited funds, I would also be interested to see if there are different mutation rates among haplogroups, as well as a number of other factors.
A report published in the New England Journal of Medicine entitled “Letting the Genome Out of the Bottle – Will We Get Our Wish?” is getting a lot of coverage elsewhere, but I thought I’d add my two cents. The report’s authors are largely concerned with quality control, clinical validity (the actual predictive value of genetic tests), and utility (the balance of family history and genetic testing) of genome scans offered by companies such as 23andMe, deCODEme, and Navigenics. They also suggest that people wait for the science to catch up before purchasing genome scans. There is an NEJM audio interview with Muin Khoury, one of the authors of the study about the subject. Note that this particular report is about medical implications of genetic testing, not about genetic genealogy (two very different topics that were very confusingly jumbled in the recent article “A High-Tech Family Tree” from U.S. News & World Report).
Scientists from the University of Utah have traced a mutation in the adenomatous polyposis coli (APC) gene to a Mr. and Mrs. George Fry, who arrived in the New World aboard the William & Mary around 1630.
The mutation, c.426_427delAT, is believed to increase the carrier’s chances of developing colon cancer from 2 in 3 by age 80, a significant increase from the normal of 1 in 24. The study is available here for FREE – thank you open access – and is entitled “American Founder Mutation for Attenuated Familial Adenomatous Polyposis.”
Scientists traced two branches (from two of the Fry’s four children) of the family back to the Fry family, one in Upstate New York and one in Utah. The family in Utah, with more than 5,000 people, has been the focus of scientific study for over 14 years because of their unfortunately high risk of colon cancer. In fact, members of the Utah branch constitute 0.15% of all colon cancer in the state of Utah!
As of the end of November, the Personal Genome Project has a newly-designed and user-friendly website. Compare the OLD site and the NEW site – what an improvement! Misha Angrist, aka genomeboy.com and one of the “First 10″ aptly called the site “PGP 2.0″.
The new site is extremely well organized and contains information about the project and about participating in the project, if one is so inclined. Since this project will contain so much personal information about each individual that joins, participants will go through an extensive consent process that will include education, physician assistance, and even an online assessment to gauge the participant’s grasp of genetics and the risks of participation, among other things. I know that the team is working feverishly behind the scenes to gather as much information as possible to create an extensive consent protocol.
PLoS Genetics has a new paper (PLoS Genet 3(11): e185. doi:10.1371/journal.pgen.0030185) that examines autosomal microsatellite markers (repeating units of base pairs) from Native American DNA:
“We examined genetic diversity and population structure in the American landmass using 678 autosomal microsatellite markers genotyped in 422 individuals representing 24 Native American populations sampled from North, Central, and South America. The Native American populations have lower genetic diversity and greater differentiation than populations from other continental regions. We observe gradients both of decreasing genetic diversity as a function of geographic distance from the Bering Strait and of decreasing genetic similarity to Siberiansâ€”signals of the southward dispersal of human populations from the northwestern tip of the Americas”
Forty advanced placement science students at Soldan International High School in St. Louis have submitted their DNA for testing with the National Geographic Society’s Genographic project. An article in the St. Louis-Post Dispatch highlights some of the statements made by the students and faculty:
“Many times students don’t see the relevance of what they’re learning,” said Assistant Principal Alice Manus, the Soldan project coordinator. “What they’re learning here will have all sorts of relevance because, really, we’re looking into their lives.”
One student, named John, had more reason to be excited about this test than most – his father died when he was only 13. “I never knew him that well,” said the Soldan sophomore. “Maybe this will tell me more about who he was and where he came from.”
Update: Ugo Perego is not affiliated withh the website mentioned in the last two sentences.
Did Joseph Smith father children with any of his plural wives? The Deseret News has a lengthy article about recent efforts by a geneticist to answer the long-debated question about the founder of the Latter Day Saint movement.
Ugo Perego, the director of operations at the Sorenson Molecular Genealogy Foundation, has used genetic genealogy in an attempt to identify or rule out potential descendants of Smith. In 2005, Perego showed that three males were not descendants of Smith, and new testing has shown that two more alleged descendants of Smith are not his true descendants.
In order to rule out descendants, it was first necessary to characterize the Y-DNA thought to belong to Joseph Smith. According to the article:
Genome Technology Online mentioned the new partnership between DNAPrint Genomics, Inc. and BioServe, a company that offers â€œthe Global RepositoryÂ®, a growing library of over 600,000 human DNA, tissue and serum samples linked to detailed clinical and demographic data from 140,000 consented and anonymized patients from four continents.â€
As part of the partnership, DNAPrint will analyze the 600,000 human samples in the Global Repository using the ANCESTRYbyDNA test.According to Richard Gabriel, the CEO and President of DNAPrint Genomics:
“By removing the question of ancestry from a clinical sample researchers can more readily evaluate which medicines will produce side effects within certain ethnic groups, and which medicines will work for the widest spectrum of a population.”
I’ve spoken before about the enormous effect that affordable SNP and whole-genome sequencing will have on genetic genealogy. In that previous article, I mentioned a study using SNP analysis to identify a person’s ancestry based on autosomal DNA (all the nuclear non-sex DNA). Another study, released today inPLoS Genetics, used SNP chips to identify SNP markers that are characteristic of a certain ancestral origins. According to the authors:
“We have developed a novel algorithm to identify a subset of SNP markers that capture major axes of genetic variation in a genotypic dataset without use of any prior information about individual ancestry or membership in a population.”
To accomplish this, the researchers:
“…studied here 274 individuals from 12 populations (20 Mbuti, 20 Mende, 22 Burunge, 42 African Americans, 42 Caucasians, 20 Spanish, 11 Mala, 20 East Asians, 20 South Altaians, 20 Nahua, 20 Quechua, and 19 Puerto Ricans). Three of these populations are admixed (Caucasians, African Americans, and Puerto Ricans). All individuals were typed using the 10K Affymetrix array.”