Genetic screening consists of a medical test or group of tests aimed at determining the presence or risks of developing a genetic disease or condition. There are several types of genetic screening tests available, depending on the purpose of the test. Prenatal or pre-implantation screening tests are commonly performed on an embryo or fetus in order to detect genetic abnormalities. Carrier screening may help to identify gene mutations, which can often help couples decide whether to have children. Any questions or concerns about the various types of genetic screening tests should be discussed with a doctor or genetic counselor.
Prenatal genetic screening is commonly performed on pregnant women in many parts of the world. These tests have a relatively high accuracy rate of detecting such medical conditions as Down's syndrome or Huntington's disease. They can also help to detect recessive genetic disorders, such as kidney disease, which may run in the family even if neither parent has an active form of the disease. Prenatal screening tests can be performed in many ways, including maternal blood tests, ultrasound, or by taking small tissue samples from the fetus.
Newborn genetic screening is often performed shortly after a baby is born. These tests involve testing a small amount of the infant's blood for some of the more common genetic disorders, which can normally be treated successfully in early childhood. Each state or country may have a different list of disorders for which the blood is tested, so any specific concerns should be discussed with a doctor or other member of the medical staff at the hospital.
Pre-implantation testing is a type of genetic screening that may be performed when the parents undergo fertility treatments such as in-vitro fertilization. This type of testing involves screening the embryo for specific genes so that only an embryo that does not contain the undesirable gene is implanted. This procedure may not be legal in all countries.
Carrier screening is yet another type of genetic screening and is often chosen by couples who are considering having children, especially if certain genetic conditions are common on either side of the family. It is possible to carry a gene for a specific disease without actually having the disease. When both prospective parents are tested, a doctor or genetic counselor can help determine the risks of having a child who is born with the genetic disorder.