Pre-conception Gene Testing

One of the few things a couple should do before getting pregnant is to submit themselves for pre-birth DNA testing. Prenatal testing is a personal choice. There are hundreds of diseases that are related to changes in our genetic code. Some of the disease-related gene mutations arerecessive, while others are dominant. Some areX-linkedor sex-linked. Some mutations are passed down in families, and some are more prevalent in individuals of certain ethnic descent. These are the reasons why prenatal gene testing is strongly encouraged for couples who have a history of familial diseases.

Prenatal screening can help couples in preventing birth defects, developmental disabilities, and other unique conditions in children. Pre-pregnancy genetic testing is quite costly but at least it will save both the future child’s life as well as save the parents from the burden and stress of caring for a sick child.

What is pre-conception gene testing?

Genetic testing pregnancy is a test for prospective or expecting parents who want to determine if they have a genetic predisposition for certain diseases. Thus, it is a screening for genetic diseases. This is usually done before the woman gets pregnant. This should be a part of a pregnancy exam of a high risk couple. Usually, blood is drawn for the test but other body fluids like saliva as well as tissues can also be used.

Genetic testing looks at a person’s genes, chromosomes, proteins and enzymes for any alterations, changes and deviations from the normal. An abnormal result on these tests could mean that the person has a genetic disorder or a carrier of a genetic disorder. If both of the couple is a carrier, this means that there is a chance that the disease can be passed on to their future children.

What are the types of genetic tests available?

Genetic tests such as pre-pregnancy DNA test have been developed for more than 2,200 diseases, of which about 2,000 are currently available for use in clinical settings. As of now, there are three types of genetic tests available:

  • Gene tests- individual genes or relatively short lengths of DNA or RNA are tested.

  • Chromosomal tests- whole chromosomes or very long lengths of DNA are tested.

  • Biochemical tests- protein levels or enzyme activities are tested.

 

Who should do a pre-conception gene testing?

Since pregnancy DNA test is a personal choice, anyone can do it as long as they have the resources to pay for it. However, there are some groups that are strongly encouraged to undergo genetic testing because they have an increased risk of having a genetic disease.

  • Age of the mother. Women age 35 or older are at a higher risk for having a child with chromosomal abnormalities or other birth defects. This is the reason why older women who get pregnant should have a pre-conception genetic testing.

  • A family history of an inherited condition. Most of genetic disorders are passed on over family generations. That’s why families with genetic disorders should undergo genetic screening before pregnancy.

  • Ancestry or ethnic background. This means that he parents-to-be might have a higher chance of carrying an inherited disorder such assickle cell anemia, which is common in people of African descent;thalassemia, which is common in people of Italian, Greek, Middle Eastern, Southern Asian, or African descent; cystic fibrosis, which is common in European Caucasians and eastern European Jews orTay-Sachs disease, which is common in people of eastern European Jews. Due to the prevalence of genetic disorders in certain races, genetic testing before conception is a good idea.

Why should you do a pre-pregnancy gene testing?

People in families at high risk for a genetic disease have to live with uncertainty about their future and their children’s future. DNA testing pregnancy can help them determine what their status really is: whether they have the disease or not or just a carrier for that disease. A negative genetic test result can provide a sense of relief for them. A positive genetic test result can help them plan for their future such as management and lifestyle changes.

For couples, genetic screening pregnancy is extremely valuable in giving reassurance about their future plans to build a family. A positive genetic result can help them make informed choices whether to have a baby or not whereas a negative genetic result will alleviate their fears.

What does a pre-pregnancy gene testing tell you?

DNA test pregnancy results give an idea of the risk for passing along genes that can trigger certain diseases in future children.

  • If both couple are not carriers for the disease, their baby will not inherit the condition.

  • If one is a carrier, but the partner is not, their baby will not inherit the condition.

  • If both couple are carriers, their child will have a 25 percent chance of inheriting the condition.

  • If one partner has the disease, there is an even greater chance that the child will inherit the condition.

However, pregnancy genetic screening is not 100% reliable in some diseases such as cystic fibrosis. Even the result is negative in cystic fibrosis, there is still a slim chance that one or both of the partners could be a carrier and can pass on the condition to their future child. The genetic test in cystic fibrosis can only identify some of the mutations in the genes that can cause the condition.

What if the couple are both carriers?

Through genetic testing before pregnancy, couples can determine their chances of passing on a genetic disease on their child. If the couple are both carriers, there’s a 25 percent chance that their future child (children) will inherit the disease but that also means there’s a 75 percent chance that the child will be disease-free. Most couples in this situation choose one of the following options.

  • Get pregnantnaturally. And follow up with pregnancy genetic testing as well as do a fetal genetic testing during pregnancy, like chorionic villi sampling or amniocentesis, which can determine whether or not the baby has inherited the disease.

  • Get pregnantnaturally, and wait until the baby is born to learn if she has the disease.

  • Get pregnant using assisted reproductive technology. With a variation of in vitro fertilization (IVF) called pre-implantation genetic diagnosis; scientists can screen your embryos in the lab and only implant healthy ones without genetic abnormalities.

  • Get pregnant using donor eggs or sperm or consideradoption.