Genetic testing is done by analyzing small blood or body tissue samples from the patient. Most body fluids and tissues can be used for testing. Genetic testing can even be performed on a developing child before birth. Pregnant women who are interested in finding out more about the potential health of their babies may choose to undergo these tests.
One of the minimally invasive screenings is a carrier screen which provides a closer look at future mother’s genes to see if she is at risk of passing a hereditary genetic disorder to the offspring. One of the tests that Dr. Ayalon recommends is Global Carrier Screen – test for carrier status of 200+ hereditary disorders that typically affect health in infancy or childhood.
Another option available to Dr. Ayalon’s pregnant patients is Noninvasive Prenatal Testing (NIPT). It is a method to determine a risk that the baby will be having certain genetic disorders. This procedure studies few DNA fragments of the fetus circulating in mother’s blood stream. NIPT allows the future parent(s) to learn if the fetus is affected or carries the following chromosomal abnormalities: trisomy 21 (Down syndrome), trisomy 18, trisomy 13. Noninvasive Prenatal Testing also allows to determine the gender of the future baby.
For a selected group of high risk patients, Dr. Ayalon will recommend one of the following procedures:
Chorionic villus sampling can be performed between the weeks 11 and 14. This procedure will inform us whether or not the baby will suffer from genetic problems. The Perinatologist carefully removes a small piece of the placenta around the fetus to be analyzed. Both amniocentesis and chorionic villus sampling carry a slight risk of inducing a miscarriage.
Between the 16th and 20th week of pregnancy, Dr. Ayalon will refer patients to a Perinatologist to perform an amniocentesis, which is one of two genetic tests that can be performed on pregnant women. During this procedure, they will carefully insert a hollow needle into the mother’s abdomen. The needle will take a small sample of amniotic fluid around the fetus. The fluid may be checked for genetic problems and can even tell the sex of the child. If the possibility of premature birth arises, then this procedure may determine how much the child’s lungs have developed.
Dr. Ayalon may recommend genetic testing if:
A couple has a family member with an inherited illness: If someone in your family has a genetic disease, you may be carrying the genes for it even if you don’t suffer from it. Some genetic illnesses are recessive, which means a person would need two copies of the gene from each parent in order for it to show up. If one parent has the problem gene, but the other does not, their children may not show symptoms of the illness.
You already have a child with a birth defect: Birth defects are not all caused by genetic problems. In fact, many of them are instead caused by toxins, infections, or trauma during the mother’s pregnancy. But if a child has already been born with a defect, Dr. Ayalon recommends the couple undergo genetic testing before choosing to have any more children.
A woman has had two or more miscarriages: Spontaneous miscarriages can occur when there are severe chromosome problems in a fetus. Multiple miscarriages can be a sign that this problem is inherited.
A woman has given birth to a stillborn child that shows signs of deformities: Some serious genetic illnesses can cause specific physical abnormalities. Not all children affected with abnormalities suffer from genetic disorders, but this could be a sign of it.
A woman over the age of 35 wants to have a child: Older women who get pregnant have increased chances of giving birth to a child with chromosomal problems.
A child suffers from medical problems: If a child suffers from medical problems in more than one body system, the cause may be genetic and can be diagnosed with testing.
Genetic testing has come a long way since it was first used to identify inherited illnesses, but they are still limited in some aspects. While genetic testing can identify particular gene problems, it cannot be used to determine how severe the problem may be. For example, a child who has been identified as carrying a problem gene for cystic fibrosis may have serious lung problems or just mild respiratory symptoms in the future.
In addition, many genetic illnesses are only partially caused by problem genes.
The rest of the causes are often found to be environmental factors. Testing for these problem genes may give you the knowledge you need to modify your lifestyle as an advantage in avoiding certain illnesses. Today, doctors are attempting to develop specific types of gene therapy in order to one day completely prevent certain diseases and illnesses. If these researchers are successful, genetic treatments of the future may be available to eliminate the symptoms of cancer and other major genetic killers.