Screening for Fragile X
As Fragile X is an inherited genetic condition, if a person finds out they have the premutation or full mutation other family members may also be carriers and/or may have a Fragile X associated condition. There is also a risk of passing the Fragile X premutation or full mutation on to children. A number of reproductive options exist for planning pregnancies and testing.
Carriers of Fragile X
With each pregnancy, female premutation carriers have a 50% chance of passing on the Fragile X gene change either as a premutation or a full mutation to a child of either sex. The chance of a female premutation carrier having a child with Fragile X syndrome depends on how many CGG repeats she carries. For each pregnancy, females with the full mutation have a 50% chance of having a child with Fragile X syndrome. Male carriers of the Fragile X premutation will pass the premutation on to all of their daughters, but none of their sons.
Learn more about: Carriers of Fragile X
Reproductive carrier screening
Genetic carrier screening helps people find out whether they have a chance of having a child with a genetic condition, such as Fragile X syndrome. Genetic carrier screening is available before pregnancy or in the early stages of pregnancy and is becoming increasingly available.
The Fragile X Association of Australia recommends Fragile X carrier testing for:
People with a family history of Fragile X syndrome or Fragile X-associated disorders, intellectual disability or autism spectrum disorders
All women considering pregnancy or in the early stages of pregnancy (during the first 12 weeks)
Any woman with primary ovarian insufficiency or experiencing early menopause.
In March 2019 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists issued a Genetic Carrier Screening statement and recommendations
Recommendation 3 of the statement (page 4):
“Information on carrier screening for other genetic conditions should be offered to all women planning a pregnancy or in the first trimester of pregnancy. Options for carrier screening include screening with a panel for a limited selection of the most frequent conditions (e.g. cystic fibrosis, spinal muscular atrophy and fragile X syndrome) or screening with an expanded panel that contains many disorders (up to hundreds).”