Karyotyping

The test can be performed on almost any tissue, including: Amniotic fluid Blood Bone marrow Tissue from the organ that develops during pregnancy to feed a growing baby (placenta) To test amniotic fluid, an amniocentesis is done. A bone marrow biopsy is needed to take a sample of bone marrow. The sample is placed into…

Follow the health care provider's instructions on how to prepare for the test.

How the test will feel depends on whether the sample procedure is having blood drawn ( venipuncture ), amniocentesis, or bone marrow biopsy.

This test can: Count the number of chromosomes Look for structural changes in chromosomes This test may be done: On a couple that has a history of miscarriage To examine any child or baby who has unusual features or developmental delays The bone marrow or blood test can be done to identify the Philadelphia chromosome,…

Normal results are: Females: 44 autosomes and 2 sex chromosomes (XX), written as 46, XX Males: 44 autosomes and 2 sex chromosomes (XY), written as 46, XY

Abnormal results may be due to a genetic syndrome or condition, such as: Down syndrome Klinefelter syndrome Philadelphia chromosome Trisomy 18 Turner syndrome Chemotherapy may cause chromosome breaks that affect normal karyotyping results.

Risks are related to the procedure used to obtain the sample. In some cases, a problem may occur in the cells growing in the lab dish. Karyotype tests should be repeated to confirm that an abnormal chromosome problem is actually in the body of the person.

Bacino CA, Lee B. Cytogenetics. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics . 21st ed. Philadelphia, PA: Elsevier; 2020:chap 98. Perle MA, Stein CH. Applications of cytogenetics in modern pathology. In: McPherson RA, Pincus MR, eds. Henry's Clinical…