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Posts Tagged ‘haplogroup’

DNA testing and genealogy results go hand in hand when a person is in search of their ancestral past. Medical information can also be obtained from DNA testing, but the way the results are analyzed is vastly different. For this reason, you must know what your intentions are before the tests are conducted.

There are specialists in the genealogy field that do nothing but analyze the results from samples. Just like with medical analysts, they know this craft and only this specialty.

In the different Y-DNA and mtDNA strands, the medical specialists are looking for specific omissions or additions of specific genes that might be present. The genealogy specialist is looking for patterns in the DNA sequencing.  These patterns are what identify the samples to which genetic family line they follow. These patterns are distinctive and are present in every sample. This includes both Y-DNA and mtDNA samples.

When studying the different samples, the analyst will be looking for the mother genetic line when the mtDNA is analyzed and the father’s genetic line from the Y-DNA. What specifically are being looked for are repeated sets of nucleotides. These patterns that are present in every sample are how they will be categorized and placed within a Haplogroup.

The reason this type of analysis can be done is because every mother passes down the mtDNA she was give by her mother to her children, which is unchanged. For the father’s lineage, the Y-DNA is passed down from father to son only. This too, is unchanged and the reason it can be traced.

This is why a male sample can trace both lines of their ancestral past but a female can’t. This is also the reason a child’s grandfather on their mother’s side can not be traced back unless a male sibling of the mother is tested.

This is the basics of DNA testing and genealogy results that can be produced from every sample.

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With Y DNA genealogy testing, a male can find out his father’s line of the family. This is because only men have the Y chromosome. The testing on this short chromosome is the Y STR test. This is helpful in discovering the past since this is passed down from father to son.

The STR is a segment of the DNA in the Y chromosome in the region that is considered Junk. The letters STR stand for short tandem repeats. The number of times a segment repeats itself is called the allele. This number is distinctive within a population which leads to surname lineage.

There are over 100 different markers in the Y DNA chromosome, but the typical one tested is the 10-67 STR marker. This identifies the haplotype that the sample belongs to. Within this testing the SNPs are notices. These are the single nucleotide polymorphism. These are observed for any changes and help identify the Haplogroup a sample is from. The mutation rate of the SNP is very low. For this reason, it is the ideal candidate for mapping a family tree.

Before a sample is tested, the number of markers to be identified should be chosen. Some only test for 12 markers, while others test for 67. For any surname project, at least 25 markers should be tested. The greater the number of markers that are identified, the more conclusive the results will be.

When a mutation occurs in a SNP, more than 1% of the population must have this same mutation for the SNP to be considered useful. If your SNP mutation is in less than 1%, then it is a personal SNP and is distinctive to your family tree.

The Y DNA genealogy testing of the SNP and the STR is the only way to determine the male ancestral line. The greater the number of markers are identified, the more accurate the results.

The genealogical DNA test that is readily available for any one to take has been refined over the years to give accurate and informative information about the ancestral past of the subject. Because of the popularity of this kind of test, the prices have decreased in recent years making the availability of even more results and family lines available for genealogist to use in their work.

The simplicity of the test makes it possible for most anyone to take the sample at their home. This helps to avoid an unnecessary expense of traveling to a certified laboratory and having a technician take the sample.

A sample is taken by rubbing a cotton swab, or a provided paddle type scraper, on a person’s cheek inside the mouth. This collects numerous cells that contains the DNA. This sampling technique is the simplest that can be used. The only decision a person needs to make is how thorough of a test that is to be conducted should be. The more markers that are identified, the more information can be discovered.

There are two distinctly different tests that can be conducted. The Y DNA is for the father’s lineage while the mtDNA is from the mother lineage. With the Y DNA, there are repeating nucleotides that are called Short Tandem Repeats (STRs) that are identified. There are over 100 of these present but the maximum testing usually only contains 67 of them for thorough results.

With mtDNA, the Single Nucleotides Polymorphisms (SNPs) are tested. These are passed down from every mother to her children without mutations. This is a stable DNA that can be traced back in time to which Haplogroup a person originates from. The basic test involves 12 markers but just like the Y DNA, up to 67 markers can be identified and used for analysis.

Depending on the thoroughness of the desired results, a genealogical DNA test can range in cost from just under $100 up to $700. The choice is that of the person desiring the results.