The importance of the carrier screen

Cystic fibrosis (CF), spinal muscular atrophy (SMA) and fragile X syndrome (FXS), three of the most common familial disorders in Australia, affect 1 in 1,000 babies; this is higher than the combined risk of trisomy 18, trisomy 13 and Turner syndrome. Many people have no family history and are unaware they are carriers.

RANZCOG now recommends that information about reproductive carrier screening for common disorders be offered to every woman either prior to conception (preferred) or in early pregnancy. An expanded carrier screen of over 400 genes is also available through Sonic Genetics. It is also recommended that individuals with an increased likelihood based on ethnicity be offered screening for haemoglobinopathies.

Carrier screening for CF, SMA and FXS

Carrier screening can identify individuals or couples at high risk of having a child with a serious heritable disorder. This test is becoming an essential part of prenatal care planning. It allows patients the opportunity to explore their reproductive options, and helps ensure they can make properly informed decisions. If a female is tested first and found to be a carrier of either cystic fibrosis or spinal muscular atrophy, a free of charge test of the relevant gene will be offered to her partner (full details will accompany the test report).

Carrier screen identifies carriers by testing for mutations that cause most cases of CF, SMA and FXS

RCS Frequency Table

Data from: Archibald A, Smith M, Burgess T, et al. Reproductive genetic carrier screening for cystic fibrosis, fragile X syndrome, and spinal muscular atrophy in Australia: outcomes of 12,000 tests. Genet Med. 2018; 20(5):513‑526

Genetic counselling

Couples tested by Sonic Genetics and found to be at high risk of having an affected child will be offered genetic counselling free-of-charge, upon referral from your doctor. Full details can be found here.