We explain the genetic testing during pregnancy with its types, definition, importance and future in detail lets read.
What are genetic tests?
Genetic testing can help doctors find faulty or missing genes . This information helps them know if a person, their partner, or their baby is prone to certain medical conditions.
Genetic testing consists of analyzing small samples of blood or other body tissue. Many different types of body fluids and tissues can be used. The type of genetic test needed to make a diagnosis depends on the condition being tested.
How is genetic testing carried out?
read also: Blood Type Genetic Rule
What genetic testing during pregnancy can be done?
When it comes to genetic testing during pregnancy that can be done before birth, there is a blood test that can be used as a prenatal screening test for some disorders. To evaluate other disorders, or if prenatal screening tests detect a possible problem, doctors may recommend amniocentesis or coronic villus sampling:
- Amniocentesis is a test that is usually done between weeks 15 and 20 of pregnancy. The doctor inserts a needle into the woman’s abdomen to remove a small amount of the amniotic fluid that surrounds the developing fetus. The fluid is tested for genetic problems and the sex of the baby can be found. When there is a risk of preterm labor , amniocentesis can show the level of maturation of the baby’s lungs. Amniocentesis is associated with a reduced risk of induction of abortion.
- Chorionic villus sampling is usually done between weeks 10 and 12 of pregnancy. The doctor removes a small sample from the placenta to evaluate the fetus for genetic problems. Since chorionic villus sampling is an aggressive test, there is a reduced risk of induction of abortion.
Why Do Doctors Recommend Genetic Testing?
A doctor may recommend genetic counseling or undergo genetic testing for any of the following reasons:
- The pregnant woman is over 34 years of age. A pregnant woman’s chances of having a child with a chromosomal problem (such as a trisomy ) increase if they are over 34 years of age. Children of older couples are at increased risk for de novo genetic mutations (those caused by an isolated genetic defect that had not previously existed in the family).
- The pregnant woman has an abnormal result in prenatal screening tests . Doctors may recommend genetic testing if prenatal screening tests have shown a possible genetic problem.
- The couple wants to have a child but one of their members or a close relative has a hereditary disease. Some people carry genes for genetic diseases, even though they have no signs of those diseases. This occurs because some genetic diseases are recessive . This means that they cause symptoms only if a person inherits two copies of the problem gene, one from each of their parents. Children who inherit a problem gene from one parent and a normal gene from the other parent will not have symptoms of a recessive disease. But they will have a 50% chance of passing the problem gene to their children.
- One of the parents has already had a child with a serious congenital anomaly. Not all children born with birth defects have genetic problems. Sometimes being exposed to a toxin (poison), infection, or trauma before birth causes a birth defect. Often times, the cause of these abnormalities is unknown. Even if a child has a genetic problem, they may not have inherited it from their parents. Some of these problems occur due to a spontaneous error in the child’s cells, not in the cells of his parents.
- The pregnant woman has already had two or more abortions. There are some chromosomal problems in the fetus that can sometimes lead to miscarriage. Having multiple miscarriages may indicate a genetic problem in the fetus.
- The pregnant woman has had a stillbirth (stillbirth) with physical features typical of a genetic disease. Many serious genetic diseases cause specific and distinctive physical problems.
- A child of the couple has medical problems that could be genetic. When a child has medical problems that affect more than one body system, genetic testing can help doctors find the cause and make a diagnosis.
- A child of the couple has medical problems that are known to be part of a genetic syndrome. Genetic testing can confirm the diagnosis. In some cases, they can also help find the type or severity of the genetic disease. These tests help doctors find the best treatment to follow.
Looking to the future
Advances in genetic testing have improved the way doctors diagnose and treat some diseases. But these tests have their limits. Genetic testing can identify particular problem genes. But they are not always useful in knowing how a problem gene will affect the person who has it. For example, in cystic fibrosis , finding a problem gene on chromosome 7 does not predict whether a child will have severe lung problems or only mild respiratory symptoms.
Also, being a carrier of problem genes is only part of the story. Many diseases develop due to a mix of high-risk genes and environmental factors, some of which the person can control. If a person knows that they carry high-risk genes, they may be able to make lifestyle changes to avoid getting sick.
Researchers have identified genes that put people at risk for developing cancers, heart disease, psychiatric disorders, and many other medical problems. The hope is that one day specific types of gene therapy will be developed to prevent some diseases and disorders.
Gene therapy is being studied as a possible way to treat conditions such as cystic fibrosis, cancer, ADA deficiency (an immunodeficiency), sickle cell disease , hemophilia, and thalassemia. Still, some patients have had serious complications while undergoing gene therapy. For this reason, research on this type of treatment is controlled so much.
There is a long time to go to be able to genetically treat some conditions. But there are also high hopes for the myriad of genetic cures that will be developed. The Human Genome Project, completed in 2003, identified all the genes (about 25,000) present on the chromosomes of humans. This genetic map is only the beginning, but it is an extremely hopeful beginning.
- What is genetics?
- What is the genetic code?
- Genetically Related Diseases
- Blood Type Genetic Rule
- Is The Child’s Genetics Entirely From Parents?
- Do Twins Have Genetics?
- Is The Child’s Genetics Entirely From Parents?
- Identification of Fetal Genetics