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Genetic genealogy is another addition to your "tools of the trade". What has genetics got to do with genealogy? Apart from the fact that both words originate from the same latin root, genus, meaning - a class, group or kind with common attributes, actually quite a lot. Especially when you're research has hit the proverbial 'brick wall', genetics may provide the solution. For instance: A valuable, and often overlooked, benefit from researching your family history is that it can assist in determining a family's predispositions for certain diseases or traits. And this in turn can be an important factor in determining ancestral links. Even by merely supplying a DNA sample to organisations such as Family Tree DNA, you may find yourself linked to a previously unknown branch of your family tree. They provide a service to amateur and professional genealogists by keeping a database of other submitter's DNA to compare to your sample. Genetic Traits
Sex-linked:
Incomplete/co-dominance
These traits may provide the clues you are looking for in your genetic genealogy quest. You may find a missing great grandmother or aunt, assuming you have a photo or at least some idea of their physical characteristics.
Another Royal Scandal? An interesting case to illustrate this point is that of Queen Victoria and her descendants. Was it a gene mutation that made her a carrier of the fatal blood disease, hemophilia, or something more scandalous? Hemophilia is known as the 'royal disease', because the defective gene made its way into every royal family in Europe through the marriage of Queen Victoria's children. Hemophilia had never entered the royal line before and it is unlikely that either of Victoria's parents had or were carriers of the disease. Only females are carriers. Mothers can pass the gene onto their daughters, whilst the male children may actually develop the disease. In Queen Victoria's case, out of nine children, two daughters were carriers (Alice and Beatrice) and a son, Leopold, was a hemophiliac. There are at least two theories as to why hemophilia suddenly appeared. The first, as mentioned, is that there was a gene mutation that randomly occurred, which is explained below. The other theory can be found at this site. Based purely on conjecture, little credence can be given, nevertheless it is not beyond the realms of possibility. Inherited Diseases A death certificate is an invaluable record in determining any family predispositions. While some diseases do run in families, not all offspring will necessarily be affected. Similarly, it may just appear out of nowhere due to gene mutation. Sounds like something out of a horror movie doesn't it? Two copies of each gene are passed on to the children. One gene comes from the father, and one from the mother. If a female has a defective gene on one of her two X chromosomes, she will be protected from its effects by the normal gene on her second X chromosome. If a male has a mutant X and a normal Y chromosome, he will be affected by a X-linked disease such as hemophilia. A recessive sex-based disease such as hemophilia occurs where only one of the copies is defective. However, the daughter then becomes a "carrier", which means that they have a 50% chance of passing the mutation on to their children. In this way some diseases may actually skip a generation. Diseases such as hemophilia are called monogenic, because, unlike some other inherited conditions where both genes need to be defective, a mutation in only one gene will cause the disease. Hemophilia occurs predominately in males (1 in 10,000). As it will only occur in females if both X chromosones are defective, the incidence is only 1 in 100,000,000. It is reputed that there are 6000 monogenic inherited diseases! Summary Just like fingerprints are to the detective, genetic traits and abnormalities can be important tools to finding that illusive ancestor. In a perfect world there would not be any mutated or defective genes to cause such terrible illnesses. But to the family historian all these aberrations can make our quest that much easier. Genetic genealogy may sound a bit 'Brave New Worldish' but don't knock it! Modern technology can be a wonderful aid in all areas of life - but also a burden. How many of us have waited on the phone for what seems like hours in a fruitless endeavour to talk to a real live human? But despite the drawbacks, there are advantages and genetic genealogy is certainly one of them.
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