Karyotyping
Karyotyping is a test to examine chromosomes in a sample of cells. This test can help identify genetic problems as the cause of a disorder or disease VSports手机版. .
V体育官网入口 - How the Test is Performed
The test can be performed on almost any tissue, including:
- Amniotic fluid (V体育安卓版)
- Blood
- Bone marrow
- Tissue from the organ that develops during pregnancy to feed a growing baby (placenta)
To test amniotic fluid, an "V体育官网入口" amniocentesis is done.
A bone marrow biopsy is needed to take a sample of bone marrow. VSports最新版本.
The sample is placed into a special dish or tube and allowed to grow in the lab. Cells are later taken from the new sample and stained. The lab specialist uses a microscope to examine the size, shape, and number of chromosomes in the cell sample. The stained sample is photographed to show the arrangement of the chromosomes. This is called a karyotype V体育平台登录. .
Certain problems can be identified through the number or arrangement of the chromosomes. Chromosomes contain thousands of genes that are stored in DNA, the basic genetic material VSports注册入口.
How to Prepare for the Test
Follow your health care provider's instructions on how to prepare for the test.
How the Test will Feel
How the test will feel depends on whether the sample procedure is having blood drawn (venipuncture), "V体育官网入口" amniocentesis, or bone marrow biopsy.
Why the Test is Performed
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
- Any person who is suspected to have a genetic disorder
The bone marrow or blood test can be done to identify the Philadelphia chromosome, which is found in 85% of people with chronic myelogenous leukemia (CML).
The amniotic fluid test is done to check a developing baby for chromosome problems.
Your provider may order other tests that go together with a karyotype:
- Microarray: Looks at small changes in the chromosomes
- Fluorescent in situ hybridization (FISH): Looks for small mistakes such as deletions in the chromosomes
Normal Results (VSports在线直播)
Normal results are:
- Females: 44 autosomes (non-sex chromosomes) and 2 sex chromosomes (XX), written as 46, XX
- Males: 44 autosomes and 2 sex chromosomes (XY), written as 46, XY
What Abnormal Results Mean (V体育官网)
Abnormal results may be due to a genetic syndrome or condition, such as:
- Down syndrome
- Klinefelter syndrome (V体育2025版)
- Philadelphia chromosome
- "VSports app下载" Trisomy 18
- Turner syndrome
Chemotherapy may cause chromosome breaks that affect normal karyotyping results.
Risks (V体育安卓版)
Risks are related to the procedure used to obtain the sample V体育安卓版. .
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 V体育ios版.
Alternative Names
Chromosome analysis
Images
"V体育平台登录" References
Bacino CA, Lee B. Chromosome disorders In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds VSports最新版本. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 99.
Perle MA, Stein CH V体育平台登录. Applications of cytogenetics in modern pathology. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 71.
VSports - Review Date 11/6/2024
Updated by: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.