What is a karyotype test?A karyotype test looks at the size, shape, and number of your chromosomes. Chromosomes are the parts of your cells that contain your genes. Genes are parts of DNA passed down from your mother and father. They carry information that determines your unique traits, such as height and eye color. Show
People normally have 46 chromosomes, divided into 23 pairs, in each cell. One of each pair of chromosomes comes from your mother, and the other pair comes from your father. If you have more or fewer chromosomes than 46, or if there is anything unusual about the size or shape of your chromosomes, it can mean you have a genetic disease. A karyotype test is often used to help find genetic defects in a developing baby. Other names: genetic testing, chromosome testing, chromosome studies, cytogenetic analysis What is it used for?A karyotype test may be used to:
Why do I need a karyotype test?If you are pregnant, you may want to get a karyotype test for your unborn baby if you have certain risk factors. These include:
Your baby or young child may need a test if he or she has signs of a genetic disorder. There are many types of genetic disorders, each with different symptoms. You and your health care provider can talk about whether testing is recommended. If you are a woman, you may need a karyotype test if you've had trouble getting pregnant or have had several miscarriages. While one miscarriage is not uncommon, if you have had several, it may be due to a chromosomal problem. You may also need a karyotype test if you have symptoms of or have been diagnosed with leukemia, lymphoma, or myeloma, or a certain type of anemia. These disorders can cause chromosomal changes. Finding these changes can help your provider diagnose, monitor, and/or treat the disease. What happens during a karyotype test?For a karyotype test, your provider will need to take a sample of your cells. The most common ways to get a sample include:
For amniocentesis:
Amniocentesis is usually done between week 15 and 20 of pregnancy. For CVS:
CVS is usually done between week 10 and 13 of pregnancy. Bone Marrow Aspiration and Biopsy. If you are being tested for or treated for a certain type of cancer or blood disorder, your provider may need to take a sample of your bone marrow. For this test:
Will I need to do anything to prepare for the test?You don't need any special preparation for karyotype testing. Are there any risks to the test?There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly. Amniocentesis and CVS tests are usually very safe procedures, but they do have a slight risk of causing a miscarriage. Talk to your health care provider about the risks and benefits of these tests. After a bone marrow aspiration and biopsy test, you may feel stiff or sore at the injection site. This usually goes away in a few days. Your health care provider may recommend or prescribe a pain reliever to help. What do the results mean?If your results were abnormal (not normal,) it means you or your child has more or fewer than 46 chromosomes, or there is something abnormal about the size, shape, or structure of one or more of your chromosomes. Abnormal chromosomes can cause a variety of health problems. The symptoms and severity depend on which chromosomes have been affected. Some disorders caused by chromosomal defects include:
If you were tested because you have a certain type of cancer or blood disorder, your results can show whether or not your condition is caused by a chromosomal defect. These results can help your health care provider make the best treatment plan for you. Learn more about laboratory tests, reference ranges, and understanding results. Is there anything else I need to know about a karyotype test?If you are thinking about getting tested or have received abnormal results on your karyotype test, it may help to speak to a genetic counselor. A genetic counselor is a specially trained professional in genetics and genetic testing. He or she can explain what your results mean, direct you to support services, and help you make informed decisions about your health or the health of your child. References
Which of the following most likely explains how the chromosomes circled in Figure One could cause a genetic disorder?Which of the following most likely explains how the chromosomes circled in figure 1 could cause a genetic disorder in the person from whom the cells were obtained? The extra chromosome will affect the levels of RNA transcribed from certain genes and the amount of protein produced from those genes in each cell.
Which of the following is most likely explanation for how a mutation in the DNA could result in the loss of the carboxyl terminus of the HBB protein?Which of the following is the most likely explanation for how a mutation in the DNA could result in the loss of the carboxyl terminus of the HBB protein? The mutation changes a codon in the coding region of the HB transcription to a stop codon such that translation terminates earlier than it should.
Which of the following best explains what process is represented in Figure 1?Which of the following correctly explains the process shown in Figure 1 ? Initiation of transcription is occurring because a strand of RNA is being produced from a DNA template strand. Figure 1 represents part of a process that occurs in eukaryotic cells.
Which statement is the most accurate description of the reaction shown in Figure 1?Which statement is the most accurate description of the reaction shown in Figure 1? It represents a polypeptide chain that is broken down through a hydrolysis reaction. Which of the following best describes the structures of carbohydrates?
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