The Forbes Series – Forbes has an excellent series of articles relating to genomic sequencing and genetic genealogy. It is well-timed and full of interesting things to think about. I highly recommend reading them all!
1. Will You Get Cancer?
2. The Telltale Tumor
3. Never Mind You – What About Me?
4. Genes of the Rich and Famous
5. Genealogy Gets Genetic
6. 12 Genes That Could Change Your Life
“Genome of DNA Pioneer is Deciphered” - This is a write-up by Nicholas Wade in the New York Times. Unfortunately, Mr, Wade used the word ‘deciphered’ in the article rather than ‘sequenced’. I’m not convinced that this was his choice, but he’s getting some flack for it. In any event, it appears that Watson’s sequence took 2 DVDs rather than just one! There’s a write-up at Nature News as well.
Additionally, the article states Dr. Craig Venter completed his own genome at the Venter Institute in Rockville, Md., and deposited in GenBank last week. There’s no way that the timing was coincidental; he obviously published his genome last week in order to beat Watson to the punch. According to a recent Nature News article (subscription only, here), an analysis of Venter’s genome will be described in a paper in the journal PLoS Biology, and he’s also writing a book, A Life Decoded: My Genome, My Life about his personal genome. The good news is that PLoS Biology is a free access journal, so the vast majority of the population who aren’t in academia can actually read and enjoy this article when it comes out! (In case you can’t tell, I’m a huge proponent of free and open publishing of data, especially that data funded with my tax dollars!!!).
genealogy etiketine sahip kayıtlar gösteriliyor. Tüm kayıtları göster
genealogy etiketine sahip kayıtlar gösteriliyor. Tüm kayıtları göster
11 Mart 2008 Salı
Genetic Genealogy and the Amish
I am a genetic genealogist because I thought it would be a fun and interesting thing to do. Some people, however, are genetic genealogists because it is a matter of life and death.
The Amish/Mennonites and Genetic Disorders
The Amish migrated from Europe (Germany/Switzerland) to the United States in the 1700s. One such group, the Old Order Amish of Lancaster County, Pennsylvania, began with 200 Swiss immigrants. Today, there are roughly 200,000 Old Order Amish. Because of the difficult lifestyle, the lack of evangelism, and the language barrier, there is essentially no conversion to the Amish religion. In addition, marriage outside the community is forbidden. As a result, the community has remained closed for over 10 generations and is still using the same 200 genomes of their founders! This is known as “founder effect,” which means that a population is started by just a small number of individuals and as a result that new population will be different (both genetically and phenotypically) from the parent population, potentially with low genetic variation.
If I were to sequence the genomes of 200 individuals that I had somehow randomly selected, I would undoubtedly uncover a number of undesirable mutations hidden in their genes. Most of these mutations would not cause any detectable phenotype because these individuals would still have a healthy copy of the mutated gene (for the DNA newbies, we all carry 2 sets of 22 chromosomes plus 2 sex chromosomes, meaning that we have two copies of most genes).
Within the Amish populations, the mutated gene perpetuates and flourishes because it is never diluted into the general public. This means that it becomes increasingly likely that two individuals, both carrying a copy of the mutated gene, will marry and produce offspring. These children then have a random chance of inheriting two mutated copies of the gene.
Crigler-Najjar Syndrome
A recent article in USA Today, “Blue glow signifies life in peril in Pennsylvania Dutch country” analyzes the effect of one of the genetic diseases threatening the Amish. Crigler-Najjar syndrome is extremely rare, with only about 110 known cases in the entire world. Almost 20% of those cases are among the Amish and Mennonite in Pennsylvania.
People with Crigler-Najjar syndrome are unable to break down bilirubin, a natural waste product from old blood cells, and it builds to a toxic level in their blood. Untreated, the condition leads to brain damage and death. The afflicted, with yellowed eyes and golden skin as a result of their condition, are forced to spend 10 to 12 hours a day in bed underneath bright blue lights to… These beds cost about $1,000, and fans must be used to keep the children cool under the intensity of the lights. Although there is no cure, a liver transplant is one option.
The Clinic for Special Children
In 1990 a clinic opened in Straburg that specialized in children with rare diseases. The Clinic for Special Children was founded by Dr. Holmes Morton, who once worked with Dr. John Crigler, the physician who first described Crigler-Najjar syndrome in 1952 with Dr. Victor Najjar. The building, located on a site that was once an Amish field, was erected by 70 local men in the traditional barn-raising manner.
According to Wikipedia:
The clinic treats about 600 children for 80 different genetic disorders or syndromes such as glutaric aciduria (GA1), maple syrup urine disease (MSUD), Crigler-Najjar syndrome (CNS), and medium-chain acyl-CoA dehydrogenase deficiency (MCADD). Not all the children are Amish; about 15% of the caseload come elsewhere, including Africa and Asia. About 75% of the children are treatable—and a third of those are highly treatable, many through techniques developed at the center
There’s a great brochure available that provides an in-depth description of the Clinic. In 2006, Dr. Morton was awarded a MacArthur Foundation “genius grant” for his work. A well-deserved honor, if you ask me. Here is a list of some of the publications associated with the Clinic for Special Children. Here are some other articles about the Clinic, including the Genome News Network, the New York Times, Scienceline, Affymetrix, and here. For more information about the Amish/Mennonites and genetic disorders, see this brief review by Laura Weeks (pdf!).
Interestingly, there is a Swiss Anabaptist DNA Project at FTDNA, but unsurprisingly there are very few samples so far. Another interesting source of information about Amish/Mennonite genetic genealogy is the Yoder Family Website, which contains links to DNA testing by members of the Yoder Family.
Hsien at EyeonDNA wrote about this topic at Genetics and Health, and if you read the article, you’ll see that even her “doctorate genealogy” has a link back to Amish studies.
The Amish/Mennonites and Genetic Disorders
The Amish migrated from Europe (Germany/Switzerland) to the United States in the 1700s. One such group, the Old Order Amish of Lancaster County, Pennsylvania, began with 200 Swiss immigrants. Today, there are roughly 200,000 Old Order Amish. Because of the difficult lifestyle, the lack of evangelism, and the language barrier, there is essentially no conversion to the Amish religion. In addition, marriage outside the community is forbidden. As a result, the community has remained closed for over 10 generations and is still using the same 200 genomes of their founders! This is known as “founder effect,” which means that a population is started by just a small number of individuals and as a result that new population will be different (both genetically and phenotypically) from the parent population, potentially with low genetic variation.
If I were to sequence the genomes of 200 individuals that I had somehow randomly selected, I would undoubtedly uncover a number of undesirable mutations hidden in their genes. Most of these mutations would not cause any detectable phenotype because these individuals would still have a healthy copy of the mutated gene (for the DNA newbies, we all carry 2 sets of 22 chromosomes plus 2 sex chromosomes, meaning that we have two copies of most genes).
Within the Amish populations, the mutated gene perpetuates and flourishes because it is never diluted into the general public. This means that it becomes increasingly likely that two individuals, both carrying a copy of the mutated gene, will marry and produce offspring. These children then have a random chance of inheriting two mutated copies of the gene.
Crigler-Najjar Syndrome
A recent article in USA Today, “Blue glow signifies life in peril in Pennsylvania Dutch country” analyzes the effect of one of the genetic diseases threatening the Amish. Crigler-Najjar syndrome is extremely rare, with only about 110 known cases in the entire world. Almost 20% of those cases are among the Amish and Mennonite in Pennsylvania.
People with Crigler-Najjar syndrome are unable to break down bilirubin, a natural waste product from old blood cells, and it builds to a toxic level in their blood. Untreated, the condition leads to brain damage and death. The afflicted, with yellowed eyes and golden skin as a result of their condition, are forced to spend 10 to 12 hours a day in bed underneath bright blue lights to… These beds cost about $1,000, and fans must be used to keep the children cool under the intensity of the lights. Although there is no cure, a liver transplant is one option.
The Clinic for Special Children
In 1990 a clinic opened in Straburg that specialized in children with rare diseases. The Clinic for Special Children was founded by Dr. Holmes Morton, who once worked with Dr. John Crigler, the physician who first described Crigler-Najjar syndrome in 1952 with Dr. Victor Najjar. The building, located on a site that was once an Amish field, was erected by 70 local men in the traditional barn-raising manner.
According to Wikipedia:
The clinic treats about 600 children for 80 different genetic disorders or syndromes such as glutaric aciduria (GA1), maple syrup urine disease (MSUD), Crigler-Najjar syndrome (CNS), and medium-chain acyl-CoA dehydrogenase deficiency (MCADD). Not all the children are Amish; about 15% of the caseload come elsewhere, including Africa and Asia. About 75% of the children are treatable—and a third of those are highly treatable, many through techniques developed at the center
There’s a great brochure available that provides an in-depth description of the Clinic. In 2006, Dr. Morton was awarded a MacArthur Foundation “genius grant” for his work. A well-deserved honor, if you ask me. Here is a list of some of the publications associated with the Clinic for Special Children. Here are some other articles about the Clinic, including the Genome News Network, the New York Times, Scienceline, Affymetrix, and here. For more information about the Amish/Mennonites and genetic disorders, see this brief review by Laura Weeks (pdf!).
Interestingly, there is a Swiss Anabaptist DNA Project at FTDNA, but unsurprisingly there are very few samples so far. Another interesting source of information about Amish/Mennonite genetic genealogy is the Yoder Family Website, which contains links to DNA testing by members of the Yoder Family.
Hsien at EyeonDNA wrote about this topic at Genetics and Health, and if you read the article, you’ll see that even her “doctorate genealogy” has a link back to Amish studies.
10 Mart 2008 Pazartesi
DNA Markers for Genealogy
DNA Markers for Genealogy - Mitochondrial DNA Genealogy
Who else wants to know about DNA markers for genealogy? Here is a simple scientific test to trace your ancestors. Did you know that DNA From One Generation To The Other Is Almost Conclusive Evidence. This breakthrough in genealogy research has been making headlines for the past several years with some astounding proof of kinship between some very prominent historical figures.
DNA testing for family tree is not only convenient, but also simple. You find a genealogy testing company either in the phone book of on the Internet. Next, make an appointment and go to the company on your assigned day, fill out the forms, pay the fee and your good to go. The DNA genealogy test starts with a mouth swab of your mouth near the cheek. Many companies give you a kit so you can do the mouth swab at home and mail in the results to the laboratory. After the laboratory tests the DNA, the results are sent back to testee.
Wide DNA Databases Compare
The company doing the genealogy DNA testing will obviously need to have access to DNA databases which they will use to make comparisons and once these comparisons show their results, the company will then send you the results regarding whom your DNA swab matched with. You should realize that each and every cell is sure to have your DNA and whether it is your sperm or egg cells or even the sex cells, you will be providing your own unique DNA for further matching.
Parents Pinpointed
Listen closely. Genealogy DNA testing is helpful in pinpointing an individual's parentage and it can be used extensively when you need to know who the mother is, and also in case of adoptions. Thus, it is easy to see how genealogy DNA testing can help with creating your family tree because your DNA will have been passed from one generation to the next and the information pertaining to your ancestors will be encoded therein.
The Egg The Sperm
When your sperm and also egg cell combine together, a new cell is created that will hold DNA from either parent and when genealogy DNA testing is performed in specialist laboratories, they will help provide evidence whether you are related to another person with a matching DNA. What's more, the chances of two persons having identical DNA are very small with the exception of identical twins which are due to the fact that their DNA is identical because the fertilized egg had split and formed two fetuses obtained from a single sperm and also from the same egg.
Cutting Edge Medical Science Genealogy DNA Testing
Just imagine, as DNA is passed from generation to generation there is very little change in its structure. This is amazing and is the primary reason to use DNA markers for genealogy testing to explore your ancestry. In no time at all, the link between families can be nailed down and makes the construction of a family tree that much more reliable and accurate. And new advances are being made in medical science to enhance and improve the DNA testing for family tree.
Who else wants to know about DNA markers for genealogy? Here is a simple scientific test to trace your ancestors. Did you know that DNA From One Generation To The Other Is Almost Conclusive Evidence. This breakthrough in genealogy research has been making headlines for the past several years with some astounding proof of kinship between some very prominent historical figures.
DNA testing for family tree is not only convenient, but also simple. You find a genealogy testing company either in the phone book of on the Internet. Next, make an appointment and go to the company on your assigned day, fill out the forms, pay the fee and your good to go. The DNA genealogy test starts with a mouth swab of your mouth near the cheek. Many companies give you a kit so you can do the mouth swab at home and mail in the results to the laboratory. After the laboratory tests the DNA, the results are sent back to testee.
Wide DNA Databases Compare
The company doing the genealogy DNA testing will obviously need to have access to DNA databases which they will use to make comparisons and once these comparisons show their results, the company will then send you the results regarding whom your DNA swab matched with. You should realize that each and every cell is sure to have your DNA and whether it is your sperm or egg cells or even the sex cells, you will be providing your own unique DNA for further matching.
Parents Pinpointed
Listen closely. Genealogy DNA testing is helpful in pinpointing an individual's parentage and it can be used extensively when you need to know who the mother is, and also in case of adoptions. Thus, it is easy to see how genealogy DNA testing can help with creating your family tree because your DNA will have been passed from one generation to the next and the information pertaining to your ancestors will be encoded therein.
The Egg The Sperm
When your sperm and also egg cell combine together, a new cell is created that will hold DNA from either parent and when genealogy DNA testing is performed in specialist laboratories, they will help provide evidence whether you are related to another person with a matching DNA. What's more, the chances of two persons having identical DNA are very small with the exception of identical twins which are due to the fact that their DNA is identical because the fertilized egg had split and formed two fetuses obtained from a single sperm and also from the same egg.
Cutting Edge Medical Science Genealogy DNA Testing
Just imagine, as DNA is passed from generation to generation there is very little change in its structure. This is amazing and is the primary reason to use DNA markers for genealogy testing to explore your ancestry. In no time at all, the link between families can be nailed down and makes the construction of a family tree that much more reliable and accurate. And new advances are being made in medical science to enhance and improve the DNA testing for family tree.
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