< BACK TO GENETIC TESTS

Karyotype

A karyotype is a visual representation of the chromosomes within a single cell. A karyotype can detect large chromosomal differences. In this section, we explain how a karyotype works and the different types of results.

Transcript

A karyotype is a visual representation of the chromosomes within a single cell. This shows what the chromosomes look like under a microscope. A karyotype can detect large chromosomal differences, like extra or missing chromosomes, rearrangements amongst the chromosomes, or structural differences within the chromosomes.

There are different types of results that may come from a karyotype.

The result may be normal.

  • A normal male result would show 23 pairs of chromosomes, with the sex chromosomes being X and Y.
  • A normal female result would show 23 pairs of chromosomes, with the sex chromosomes being two X’s.

Abnormal results could include:

  • Extra or missing whole chromosomes
  • Extra or missing parts of chromosomes
  • Or rearrangements of chromosomal material

These types of results may be present in all or some of the cells. When only some cells are abnormal, it is called mosaicism.

You will not typically see a picture of the chromosomes for your results. Results often just say the number of chromosomes and what the sex chromosomes are.