What you can expect

By Mayo Clinic Staff

Your doctor, medical geneticist or nurse practitioner may administer a genetic test. Depending on the type of test, a sample of your blood, skin, amniotic fluid or other tissue will be collected and sent to a lab for analysis.

  • Blood sample. A member of your health care team obtains the sample by inserting a needle into a vein in your arm. For newborn screening tests, a blood sample is taken by pricking your baby's heel.
  • Cheek swab. In some situations, a swab sample from the inside of your cheek is collected for genetic testing.
  • Amniocentesis. This prenatal genetic test relies on a sample of the amniotic fluid. During amniocentesis, your doctor inserts a thin, hollow needle through your abdominal wall and into your uterus. A small amount of amniotic fluid is then withdrawn into a syringe, and the needle is removed.
  • Chorionic villus sampling. For this prenatal genetic test, your doctor takes a tissue sample from the placenta. Depending on your situation, the sample may be taken with a tube (catheter) through your cervix or through your abdominal wall and uterus using a thin needle.
July 19, 2013