Karyotyping is a test that helps find genetic problems. It is usually carried out to examine abnormalities, genetic disorders or defects.
Ameeta had an unexpected miscarriage. She could hardly grasp the
reality. Soon her doctor prescribed some test to be carried out. One of
them was blood karyotyping. She was waiting for her reports to arrive. But at the back of her mind she had this tiny question popping, what is karyotyping?
There are many pre natal tests that doctors may suggest. Understanding
these tests can lessen your anxieties, help you understand the problem
better and let you make corrections as required. Once you know what
your doctor is trying to do for you, you can co-operate better. Read on to understand karyotyping and be in sync with what you are doing.
What is Karyotyping?
Karyotyping is one of the many techniques that help study the human genes for several genetic diseases. Karyotyping
comes from the word karyotype. Karyotype is a complete profile of an
individual's chromosomal set up. Any changes in the arrangement of a
karyotype helps doctors study possiblegenetic disorders. In simpler terms, karyotyping is a close study of chromosomes.
What does a Karyotype Show?
A karyotype shows the details of the chromosomes. Karyotyping identifies and helps determine the sex of an unborn child. When doctors study a human karyotype they look for some significant features. Here are a few important ones.
- Check if the 46 chromosomes are present
- Check the presence of the two identical chromosomes and 2 sex chromosomes
- Check if there are any missing or rearranged chromosomes
What a Karyotype does not show?
While a karyotype provides significant in-depth insight into the chromosomes there are some things it will not show. They are:
- Presence and location of small mutations. So if diseases are caused by small mutations they cannot be predicted
- Individual DNA strands or genes
- The number of genes in any given area of a chromosome
How is blood karyotyping performed?
There are usually no special requirements before performing the test.
It is performed on a sample of blood, bone marrow, the amniotic fluid
or the tissue from the placenta. Blood is drawn from the body if it
requires blood sample. Amniocentesis
is carried out to test amniotic fluid. A bone marrow test would require
a bone marrow biopsy. The given sample is placed on a tray and allowed
to grow in the confines of a laboratory. The cells from the growing
sample are then stained. The stained sample is closely examined to
study the chromosome arrangement.
Predicting disorders with karyotyping
A normal human being has 46 chromosomes, 22 autosomes and two
sex chromosomes. When there is a disharmony between this set up, a genetic disorder
occurs. Too many chromosomes, missing chromosomes or mixed up bits of
chromosomes show the presence of a problem. The state of the
chromosomes helps predict any possible genetic disorder in an unborn
child. Chromosomes carry information that is passed to the cell. Extra
copies of the information, mixed information or missing information can
inform about anyabnormalities or defects.
What makes blood karyotyping helpful?
Blood Karyotyping is a very helpful method of studying
chromosomes and predicting genetic disorder. It counts the number of
chromosomes and looks for any structural changes in chromosomes. It
informs if the unborn babywill suffer from a genetic disorder or not.
It is often used during pre-natal testing and diagnosing possible
genetic diseases. It is extremely helpful for those who have suffered
the loss of a child through a miscarriage. For couples coping with a miscarriage karyotyping can mean identifying and correcting problems to give birth to a healthy child.