Gene testing how does it work

For example, a procedure called a buccal smear uses a small brush or cotton swab to collect a sample of cells from the inside surface of the cheek.

The sample is sent to a laboratory where technicians look for specific changes in chromosomes, DNA, or proteins, depending on the suspected disorder. The laboratory reports the test results in writing to a person's doctor or genetic counselor, or directly to the patient if requested. Newborn screening tests are done on a small blood sample, which is taken by pricking the baby's heel. Unlike other types of genetic testing, a parent will usually only receive the result if it is positive.

If the test result is positive, additional testing is needed to determine whether the baby has a genetic disorder. Before a person has a genetic test, it is important to understand the testing procedure, the benefits and limitations of the test, and the possible consequences of the test results.

The process of educating a person about the test and obtaining permission is called informed consent. Individuals interested in direct-to-consumer genetic testing do not need to go through a health care provider to obtain a test, but they can get it directly from the testing company.

After undergoing direct-to-consumer genetic testing, people who test positive for a condition or are found to be at higher risk of developing a disorder are encouraged to follow-up with a genetic counselor or other health care provider. Other chapters in Help Me Understand Genetics. Genetics Home Reference has merged with MedlinePlus. Let your dog chew a swab. Then ship that sample off in the mail. If you got it for your dog, the test might say whether Fido has any German shepherd, corgi or poodle in its family tree.

It might also identify whether you or your dog faces an elevated risk for certain diseases such as kidney problems. Such wizardry is known as DNA sequencing. Those letters — called nucleotides — are the chemicals that make up DNA. There are only four letters: adenine A , cytosine C , thymine T and guanine G. Adenine only pairs with thymine.

Cytosine only pairs with guanine. This might seem like a very limited alphabet. But the order in which those letters line up within a long string of DNA will spell out genetic instructions that tell each cell of the body which molecules it should make. Portions of each strand are known as sequences as in sequences of letters. With billions of nucleotides, millions of those letters are going to be different, even between parents and children or brother and sister.

For instance, some people have one letter — say an A — at the place in some sequence where others might have a G or C. The new spelling might cause the gene to make a different protein. One tiny spelling tweak could contribute to making you taller or change the color of your eyes.

Another might put you at a higher or lower risk for some disease. When compared to someone else, the precise spelling of sequences in your DNA can show how closely related you two are. There are many companies that will test DNA — for you and even your cat or dog no fish, gerbils or birds, yet.

Last Updated: August 12, This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.

A kidney infection happens when bacteria or a virus get into one or both of your kidneys. It can…. Visit The Symptom Checker. Read More. Tips for Healthy Children and Families. Diet and Exercise for a Healthy Heart.

Effects of Sun Exposure. Kegel Exercises for Your Pelvic Muscles. Passing Healthy Habits on to Your Children. To diagnose a disease or a type of disease.

To determine the cause of a disease. To determine treatment options for a disease. To find your risk of getting a certain disease that possibly can be prevented. To find your risk of passing a disease to your children. To screen your embryo, fetus, or baby. Path to well being Talk to your doctor if you think you are at risk for an inherited disease. Things to consider Genetic testing has pros and cons. Some benefits of genetic testing include: You might be less worried about getting a certain disease.

You might be able to change your lifestyle to reduce your risk. You might know how to move forward with family planning. You might be able to get treatment to prevent the disease. This could include medicine or surgery.