Chilton Medical Center - ATLANTIC HEALTH SYSTEM
Decrease (-) Restore Default Increase (+)  font size
PrintEmail
Search Health Information   

Karyotyping
Karyotyping


Karyotyping

Definition:

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.



Alternative Names:

Chromosome analysis



How the Test is Performed:

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 a special dish or tube and allowed to grow in the laboratory. Cells are later taken from the new sample and stained. The laboratory 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.

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.



How to Prepare for the Test:

Follow the 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 ), 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

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 hybridisation (FISH): looks for small mistakes such as deletions in the chromosomes


Normal Results:

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


What Abnormal Results Mean:

Abnormal results may be due to a genetic syndrome or condition, such as:

This list is not all-inclusive.

Chemotherapy may cause chromosome breaks that affect normal karotyping results.



Risks:

Risks are related to the procedure used to obtain the sample.

In some cases, a problem may occur to 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.



References:

Bacino CA. Cytogenetics. In: Kliegman RM, Stanton BF, St. Geme J III, Schor N, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 76.




Review Date: 11/25/2014
Reviewed By: Chad Haldeman-Englert, MD, FACMG, Wake Forest School of Medicine, Department of Pediatrics, Section on Medical Genetics, Winston-Salem, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
adam.com


Morristown Medical Center
100 Madison Avenue
Morristown, NJ 07960
973-971-5000

Overlook Medical Center
99 Beauvoir Avenue
Summit, NJ 07901
908-522-2000

Newton Medical Center
175 High Street
Newton, NJ 07860
973-383-2121

Chilton Medical Center
97 West Parkway
Pompton Plains, NJ 07444
973-831-5000

Hackettstown Medical Center
651 Willow Grove Street
Hackettstown, NJ 07840
908-852-5100

Goryeb Children's Hospital
100 Madison Avenue
Morristown, NJ 07960
973-971-5000

Atlantic Medical Group
1-800-247-9580

Morristown Medical Center

100 Madison Avenue
Morristown, NJ 07960
973-971-5000

Overlook Medical Center

99 Beauvoir Avenue
Summit, NJ 07901
908-522-2000

Newton Medical Center

175 High Street
Newton, NJ 07860
973-383-2121

Chilton Medical Center

97 West Parkway
Pompton Plains, NJ 07444
973-831-5000

Hackettstown Medical Center

651 Willow Grove Street
Hackettstown, NJ 07840
908-852-5100

Goryeb Children's Hospital

100 Madison Avenue
Morristown, NJ 07960
973-971-5000

Affiliated Providers

Atlantic Medical Group

More than 600 community-based health care providers.
1-800-247-9580

© 2016 Chilton Medical Center, 97 West Parkway, Pompton Plains, New Jersey 1-973-831-5000