Genetic Carrier Screening

What is genetic carrier screening?

It is a test to detect a genetic disorder which may not exhibit symptoms.

Why is it important?

Many people are carriers of one or more recessive genetic conditions. While they do not necessarily suffer from the disease, the gene lies dormant in their body and can be inherited by their children, who may have a higher risk of being affected by the disease if both parents are carriers of the same genetic disorder. Symptoms may not be expressed until the later stages of childhood, which may delay treatment and medical attention.

How does it work?

Genetic carrier screening can test for up to hundreds of genetic conditions, including common ones like cystic fibrosis, fragile X, duchenne muscular dystrophy (DMD) and alpha thalassemia, with a small blood sample. Anyone can opt for carrier screening before or during pregnancy, although those with a known family history of genetic diseases may be at a higher risk of carrying the disease. The results are available in about three weeks.

What to do if you are at risk?

Some measures can be taken, especially if you plan to conceive and do not want to put your child at risk. For example, you can use a sperm or egg donor who is not a carrier of the condition, or undergo in vitro fertilisation (IVF) with preimplantation genetic diagnosis (PGD), which screen for embryos without the genetic abnormalities before implantation to prevent pregnancies with affected babies. Prenatal genetic tests such as chorionic villi sampling and amniocentesis can also be done.


25% or 1 in 4

Your chances of having an affected child with each pregnancy if you and your partner are both carriers of the same recessive genetic disease