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    Karyotype Test

    Results

    Karyotype is a test to identify and evaluate the size, shape, and number of chromosomes in a sample of body cells.

    Results of a karyotype test are usually available within 1 to 2 weeks.

    Karyotype
    Normal:
    • There are 46 chromosomes that can be grouped as 22 matching pairs and 1 pair of sex chromosomes (XX for a female and XY for a male).
    • The size, shape, and structure are normal for each chromosome.
    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.

    What Affects the Test

    If you are being treated for cancer, the results of a karyotype test may not be accurate. Chromosomes may be damaged by some types of cancer treatment.

    What To Think About

    • If the results of karyotype are abnormal, other family members may be advised to have the test.
    • A sample taken by gently swabbing the tissues inside the cheek (called a buccal swab) sometimes is used for a karyotype test. But results from buccal swabbing are less accurate than other types of karyotype tests.
    • Sometimes a karyotype test is combined with other genetic tests to provide more specific information about genetic problems. To learn more, see the topic Genetic Test.

    Other Works Consulted

    • Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.

    • Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

    • Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby.

    • Skirton H, Patch C (2009). Genetics for the Health Sciences: A Handbook for Clinical Healthcare, 2nd ed. Oxfordshire, UK: Scion Publishing.

    ByHealthwise Staff
    Primary Medical ReviewerKathleen Romito, MD - Family Medicine
    Specialist Medical ReviewerSiobhan M. Dolan, MD, MPH - Reproductive Genetics

    Current as ofMarch 12, 2014

    1 | 2 | 3

    WebMD Medical Reference from Healthwise

    Last Updated: March 12, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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