Dedicated genetic testing for fragile X syndrome
In addition to a comprehensive screening for more than 110 genetic disorders (Inheritest), we also offer single gene screening for certain disorders, such as fragile X syndrome, the most common inherited form of intellectual disability, and a common known cause of autism.1
Fragile X syndrome is found among a variety of ethnic groups,2 and can occur in families with no history of intellectual disability. Approximately one in 260 women2 and one in 800 males3 in the general population is a fragile X carrier. Females who are carriers are at increased risk to have affected children and have an increased risk for fertility problems, including early menopause. Male or female fragile X carriers may develop tremors and balance problems later in life, but male carriers are not at risk to have an affected child.
Choice in testing for fragile X syndrome
At Integrated Genetics, our focus is offering the right test at the right time to the right patient, which is why we offer two types of testing for fragile X: carrier screening and diagnostic.
Carrier screening for fragile X syndrome is commonly used for individuals both when there is no family history suggestive of the syndrome, and also for unaffected individuals who may have a family history of fragile X syndrome, fragile X-associated disorders (primary ovarian insufficiency, or late-onset ataxia), or unexplained intellectual disabilities, developmental delay, or autism.
We’re able to perform diagnostic tests for fragile X syndrome both during pregnancy (prenatal testing) and after a child is born (pediatric testing).
Prenatal testing is for female carriers of fragile X syndrome who are currently pregnant, or women with primary ovarian insufficiency or failure, premature menopause, or infertility associated with elevated FSH levels before the age of 40 with no known cause. Pediatric diagnostic testing is typically for individuals with unexplained intellectual disabilities, developmental delay, or autism.
Sample requirement and turnaround time
Carrier screening and diagnostic testing for symptomatic individuals requires a blood sample or mouthwash and results are typically ready within 5 to 8 days (7 to 10 for diagnostic tests).
- Carrier Screening for Genetic Conditions. ACOG Committee Opinion, Number 691. March 2017.
- Carrier Screening for Fragile X syndrome. ACOG Committee Opinion, Number 469. October 2010.
- Dombrowski, C., et al. Premutation and intermediate-size FMR1 alleles in 10,572 males from the general population: loss of an AGG interruption is a late event in the generation of Fragile X syndrome alleles. Hum Mol Genet 2002; 11(4):371–378.