What is karyotyping / chromosome analysis?
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The process of performing a karyotype or chromosome analysis examines, labels, and numbers the chromosomes in a person’s cells. Chromosome analysis can be done on blood, tissue, or cells from amniotic fluid (the liquid that surrounds the fetus in the womb). Chromosome analysis is used to determine whether :
The chromosomes of an adult have an abnormality that can be passed on to a child.
A chromosome defect is preventing a woman from becoming pregnant or causing her to miscarry.
A chromosome defect is present in a fetus or infant.
Chromosomal problems may have caused a fetus to be stillborn.
The cause of a birth defect or disability is a chromosomal defect. |
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How is karyotyping performed?
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The test can be done on a sample of peripheral blood (venipuncture) and bone marrow (bone marrow biopsy). Chromosome analysis is performed after cultivating of sample in a culture medium, harvesting the metaphase chromosomes, stained and viewed under the microscope. They are photographed to provide a karyotype, which shows the arrangement of the chromosomes. |
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What result can we expect?
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The test is interpreted as normal and abnormal karyotyping.
Normal: There are 46 chromosomes that can be grouped as 22 matching pairs and 1 pair of sex chromosomes (XX for a female, XY for a male). The size, shape, structure, and location of each chromosome are normal.
Abnormal: There are more than or fewer than 46 chromosomes. The shape or size of one or more chromosomes is abnormal. A chromosome pair may be broken or incorrectly separated. |
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