There are various situations where one might consider carrying out a Y Chromosome test.  It is also quite common that the Y Chromosome is used for identification purposes or to detect the presence of males from another family. 

It is most commonly used in situations where the there is question of paternity when the father is deceased or not available.  Two male persons directly descending from the same paternal bloodline should carry the same Y Chromosome.  This can help in obtaining an accurate yes or no in cases where the two males want to determine the lineage.  It is most commonly used to determine if two male brothers share the same father but it can also be used in between cousins, uncle and nephew and also grandfather and male grandchildren.  In fact it is nor possible to determine the exact relationship between the two males as all males from the same paternal lineage all share the same Y Chromosome.  If there is certainty that two male siblings could not have been fathered by two related possible fathers, then this test is very useful to determine paternity when the father is not available or willing.

What is Y-Chromosome

The Y Chromosome is also known as the male Chromosome.  Through the Y Chromosome, the main characteristics pertaining to the male sex are determined.  The Y Chromosome has a lower amount of genes in comparison to the X Chromosome.  Infact the Y Chromosome carries only 70 – 200 genes whilst the X Chromosome carries in between 900 – 1400 genes.  Males have 23 pairs of XY Chromosomes.  Whilst some genes are only specific to the Y Chromosome, some are also in common in both the Y and the X Chromosomes.  Certain male specific disorders, like male infertility and testicular problems are directly linked to the Y Chromosome.

What does the Y-Chromosome test determine?

All males, who are directly related through an unbroken male line, all carry the same Y Chromosome. When testing the Y Chromosome of two male persons we are able to identify if these two individuals actually have the exact same Y Chromosome or not. The Y Chromosome test can therefore be carried out in between different male family members (Eg Cousins, Brothers, Uncle and Nephew or Grandfather and Grandchild).  This test can be very useful in determining the paternity when the father is not available, in cases where there are two male siblings and the paternity of one is certain.  Any male family member who is directly linked to the alleged father who is either deceased of not available, can assist in determining the paternity by comparing the Y Chromosome with that of the male child in question.

What precautions need to be considered with the Y Chromosome Test?

It is very important to know that a Y Chromosome test does not give you a definite answer specific to any type of relationship.  It purely based on an assumption of already known information.  When two male persons are tested and their Y Chromosome match, it does not automatically mean that they are cousins.  It does however mean that they are related through a direct male line.   In the case of two male siblings, if when tested, they are found to have the same identical Y Chromosome you can only assume that they share the same father if it certain that no other direct male relative to the alleged father could have also fathered them (example uncle, grandfather etc).  All male members that are connected through the same Y Chromosome belong to the same family the relationship between them could be anything from uncle and nephew to brothers.

What else can the Y Chromosome Test be used for?

The Y Chromosome test can also be used in other situations in cases of identify persons or in detecting male presence.  It can be extracted out of various non-standard samples and is also a popular choice for to detect the male presence on suspicious stains on sheets or undergarments in cases of infidelity.  The Y Chromosome can also be used in the paternal lineage test in order to find out more about the paternal origins of their Y Chromosome.