What are the different types of genetic testing?
Diagnostic testing
If you have symptoms of a disease that may be caused by genetic changes, genetic testing can reveal if you have the suspected disorder. For example, genetic testing may be used to confirm a diagnosis of cystic fibrosis or Huntington’s disease.
Presymptomatic and predictive testing
If you have a family history of a genetic condition, getting genetic testing before you have symptoms may show if you are at risk of developing that condition. For example, this type of test may be useful for identifying your risk of BRCA gene-related breast cancer, and bowel cancer.
Carrier testing
If you have a family history of a genetic disorder – such as sickle cell anaemia or cystic fibrosis – or you are in an ethnic group that has a high risk of a specific genetic disorder, you may choose to have genetic testing before having children.
Pharmacogenetics
If you have a particular disease, this type of genetic testing may help determine what medication and dosage will be most effective and beneficial for you.
Prenatal testing
If you are pregnant, tests can detect some types of abnormalities in your baby’s genes. Downs syndrome and trisomy 18 syndrome are two genetic disorders that are screened for as part of prenatal genetic testing. Traditionally this is done looking at markers in a blood or amniocentesis test. Newer testing called ‘cell-free DNA’ testing looks at a baby’s DNA via a blood test done on the mother.
Newborn screening
This is the most common types of genetic testing. Newborns are tested for certain genetic and metabolic abnormalities that cause specific conditions. This type of genetic testing is important because if results show there is a disorder such as congenital hypothyroidism, sickle cell disease or phenylketonuria (PKU), treatment can begin right away.
Preimplantation testing
Also called ‘preimplantation genetic diagnosis’, this test may be used when you attempt to conceive a child through in vitro fertilisation. The embryos are screened for genetic abnormalities. Embryos without abnormalities are implanted in the uterus in hopes of achieving a normal pregnancy.
