The Y chromosome is one of the two sex chromosomes and determines the male sex in humans. Men have one X and one Y chromosome (XY), while women have two X chromosomes (XX). It contains important genes such as the SRY gene, which is responsible for the development of male sexual characteristics.

Why is it important in laboratory medicine?

In laboratory medicine, the Y chromosome is tested to clarify various medical questions. For example, it helps to determine the genetic sex of newborns with unclear sexual characteristics. It is also used in the diagnosis of chromosomal disorders such as Klinefelter syndrome (XXY) . It is also important in the investigation of infertility in men, especially if there are no or few sperm.

How is it tested in Germany?

In Germany, there are several methods for testing the Y chromosome:

• Chromosome analysis: A blood sample is taken, the cells are cultured and the chromosomes are examined under a microscope to check their number and structure.
• Molecular genetic testing: DNA is extracted from blood or an oral mucosal sample, and specific regions of the Y chromosome are amplified using a method called PCR to test genes such as SRY.
• Microdeletion tests: These tests look for small deletions in the Y chromosome that may be associated with infertility and are performed on men with little or no sperm.

All these tests must comply with the German quality guidelines (RiliBÄK) to ensure accurate and reliable results.

What do the results mean?

The results show whether the Y chromosome is present and whether there are any deviations. For example:

• A normal XY pattern means that the person is male.
• Missing or additional Y chromosomes can indicate diseases such as Klinefelter syndrome.
• Microdeletions can explain why a man is infertile.

These tests help doctors to make the right diagnosis and plan the best treatment.

Matching:

Need for information on prenatal examinations for chromosomal disorders – MedLabPortal

Complete recombination map of the human genome created – MedLabPortal

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Gender note. The personal designations used in this text always refer equally to female, male and diverse persons. Double/triple references and gendered designations are avoided for the sake of better readability ected.