Genealogical DNA test is used to see individual’s genome on a specific point to determine the genealogical relationships. This gives us the information of groups of ethics of each and every individual that may be related to each other.
In common term, they do not give any knowledge about the condition of a person or about any disease.
There are many different types of genealogical DNA tests which are used in today’s life, which greatly study the each and every part of the genome that is used in various kinds of genealogical researchers.
3 main types of genealogical tests are known namely-
- Autosomal and X- DNA
- Y- DNA
Firstly we will discuss Autosomal test, this test seen at chromosomes 1-22 and x. Chromosomes 1-22 are inherited by both our parents and our ancestors. Chromosome X has a special pattern of inheritance. Estimation of ethnicity also included in the test. Y- Chromosome represent Y- DNA which is inherited from father to son, carried by males and can be explored by paternal line. Mitochondria represent in mtDNA, which is inherited from Mom to son and can diverse the maternal line. For the estimation of ethnicity, Y-DNA and mtDNA cannot be used but they can be used to determine the haplogroup that is related to particular ethnic group or area.
Autosomal DNA test –
This DNA (22 pairs of chromosomes) do not contribute to sex. Inheritance of this is equal from parents and grandparents. This test can test nearly 700,000 single nucleotide polymorphisms (SNPs). Autosomal DNA reunites in every generation. That’s why the number of markers decreases near about half in each generation.
X chromosome test –
Males and females both got an X- chromosome from their mom, but only women get an X- chromosome from the father. X- Chromosome undergoes recombination process in every generation (exception for a father to baby girl x – chromosomes which travel without any change).
There are special things by which we can describe the patterns of x- chromosomes DNA inheritance for both man and women.
mtDNA testing –
Mitochondrial DNA has nearly 16,569 base pairs (the number can be changed by addition and deletion mutations). The mitochondrion is a part of the human cell which has its own DNA. This DNA is travel from mom to her children, because of this we can find out the maternal ancestor by the use of mtDNA.
Y- DNA test –
This test is most appropriate and ancient DNA tools for genealogical purposes. Y- Chromosome is the 23rd pair of chromosomes, the only man has Y- chromosome whereas females have two X chromosomes at 23rd place. The results of man test compared with another man give the information about the common ancestors both the individuals shared.
Types of DNA tests – STRs and SNPs
STRs – (short tandem repeat) in this test a small part of DNA is studied for repeating patterns.
SNPs – (single nucleotide polymorphism) it is determined by a change in a single nucleotide of DNA sequence. It gives us the extra information about the relation between two individual.