Y-Chromosome Testing

The Y- Chromosome is found only in males and is always found paired with an X-chromosome.  The Y-Chromosome is the chromosome which determines sex and is always found with an X chromosome.   In issues relating to paternity, paternal lineage and relationship testing it is the sex determining region Y (SRY gene) that is analysed.  You may find more information about this on DNA Relationship Testing.  The Y chromosome constitutes around 2% of the total DNA found in cells.  The Y-chromosome contains information about sperm cell development, and thus missing parts of the chromosome means that fertility is affected.