Karyotype Genetic Test
Reviewed
A karyotype test looks at the size, shape, and number of chromosomes in a sample of cells to see if you have a full set of 46 chromosomes, and to look for changes in chromosome structure that may cause health problems, growth issues, or genetic disorders. It is often used when planning to have children, during pregnancy, or to help diagnose certain cancers and blood disorders.
Preparation and collection
For a blood test or cheek swab, no special preparation is needed. For amniocentesis or CVS, you may need to drink extra fluid and not urinate before the test so your bladder is full. For a bone marrow test, ask your provider for instructions.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- A normal result does not rule out all possible genetic or chromosome conditions.
- Additional testing may be needed to confirm the specific diagnosis and understand its implications.
- A blood test has very little risk; slight pain or bruising at the needle site, but symptoms usually go away quickly.
- A cheek swab has no risk.
- Amniocentesis and CVS are safe but have a slight risk of causing miscarriage.
What to do next
If you have received abnormal results or are considering testing, it may help to talk with a genetic counselor, who can provide information about how genetic conditions might affect you or your family and help with support services and informed decisions about treatment or management options.