Genetic Testing: Types and Procedures

Gene studies or genetic testing is defined as the analysis of the individual’s DNA (Genes, chromosomes or a protein) to find out the genetic changes or variations which are associated with genetic disorders such as Hemophilia, muscular dystrophy and birth defects like spina bifida or cleft lip.

It is used to diagnose genetic diseases, assess the risk of diseases, help guide treatment decisions, and provide preventive measures.

Table of Contents

How Genetic Testing is done?

Genetic testing uses a sample of blood, saliva, hair, and skin. However, in pregnant women, it is done with the help of amniotic fluid or the placenta.

Before taking this test, it is important to know the testing procedure, its benefits, and its limitations. It is also important to give informed consent before starting the test.

Why one should do a genetic test?

It helps the doctor to identify the cause of the disease.
It helps to find the risk of the disease in the future.
It helps to find the right and best treatment for the patient.
It helps to provide better counselling for the patient.
It helps to find out whether the patient can pass the disease on to his/her children

What are the different 8 types of genetic tests?

Diagnostic gene testing – This test is done to identify the cause of a patient’s disease. It is used to find out the specific gene or chromosome responsible for the disease. It can be done before birth or any time after birth.
Clinical gene testing – This test is suggested by the specialist and performed in a certified lab.
Pre-symptomatic testing – This test is done to find out the risk of any disease in the future.
Carrier testing – This test is done to identify the DNA variants responsible for a disease if both parents pass these variants on to their children. Carriers usually do not have symptoms of that disease. This type of testing is commonly done in individuals who have a family history or a specific genetic disorder.
Prenatal testing – This test is done during pregnancy to determine whether the baby will have a disease or not. In some cases, this prenatal testing can lessen a couple’s uncertainty or help them make a decision about a pregnancy.
Newborn Screening testing – This test is done to determine whether the baby has a certain disease or not. It is done one or two days after the baby is born.
Research genetic testing – This test is done for research purposes in medicine. It helps to study the involvement of individual genes or groups of genes in health and disease.
Pharmacogenomic testing – This test is done to find out the suitable medicine and dose for the patient based on his/her DNA variants.

What do the results of genetic tests mean?

A positive test result means that there is a change in a particular gene, chromosome, or protein of the test. This result may confirm the diagnosis that the person is a carrier of that particular gene variant, has a risk of developing a disease like cancer, and should undergo further tests and consultation.

A Negative test result means that there is no change in a particular gene, chromosome or protein. This result shows that the person is not affected by any particular genetic disorder.