- What is a karyotype?
- Karyotype test - when is it performed? Indications for the test
- Karyotype test - what is it and what does its course look like?
- Karyotype test - waiting time for results
The karyotype test, or cytogenetic test, allows you to evaluate the number, size and structure of all chromosomes in a given person. The karyotype test allows you to detect abnormalities responsible for the occurrence of birth defects in a child, e.g. Down's syndrome, as well as for fertility problems or habitual miscarriages. Check what the karyotype test looks like and what is a karyotype.
Karyotype test , or cytogenetic test, is a genetic test recommended by the Polish Gynecological Society. If you are planning to become pregnant, you are worried that your child may have a genetic defect or that your family has had a genetic condition, it is worth having a karyotype test.
What is a karyotype?
Karyotype is the complete set of chromosomes present in the cells of the body of every living thing (only those with a cell nucleus). The number of chromosomes in the karyotype varies from species to species. A he althy person has 46 chromosomes linked in 22 pairs. There are also two types of chromosomes in the karyotype: non-sex autosomes and sex chromosomes, i.e. allosomes.
Abnormalities in the karyotype (e.g. the absence or excess of a chromosome) mean that such a person has the so-called chromosomal aberration (mutation). It can, in turn, cause a serious genetic disease, such as Down's syndrome, Edwards' syndrome, Patau's, or Klinefelter's syndrome. It can also make it difficult for a couple to become pregnant or prevent a woman from maintaining her pregnancy.
Karyotype test - when is it performed? Indications for the test
The karyotype test should be performed primarily by couples who, despite many months of efforts, cannot conceive a child. Cytogenetic analysis then helps to determine whether the difficulties in getting pregnant are a consequence of some defect in the karyotype of the woman or her partner. This defect does not have to cause disease symptoms, but it may cause fertility disorders. Based on the result of such a test, the geneticist estimates the chances of a given couple of having their own children. It also indicates the methods of treatment used in their case of infertility.
The karyotype test is also used in the diagnosis of neoplastic diseases.
Forthe cause of the miscarriage can also be determined by the karyotype test. Therefore, it is recommended for all women with more than 2-3 pregnancy losses.
The test of the karyotypeis also performedin childrenwhose external appearance and behavior (the so-called phenotype) suggest some undefined genetic disease. People who have relatives with genetic defects in their family should also consider karyotyping. Moreover, they are performed in pregnant women, especially if during prenatal examinations, e.g. ultrasound, the doctor found abnormalities in the development of the fetus.
Karyotype test - what is it and what does its course look like?
A few milliliters of peripheral blood taken from the patient are enough to perform the karyotype test. This study also does not require any special preparation. You do not need to be fasting before sampling as for normal morphology. If the karyotype is to be performed during pregnancy, the sample is either the amniotic fluid or a fragment of the chorion. If the karyotype test is performed to diagnose cancer, the bone marrow (e.g. in the case of leukemia) or a fragment of the cancerous tumor is collected from the patient.
Karyotype test - waiting time for results
Due to the fact that the cytogenetic test requires the cultivation of an appropriate number of cells, it usually takes about 3 weeks for the result of the analysis. It contains a graphic representation of all chromosomes in the karyotype of the examined person and information whether it is normal or not.