Fragile X Carrier Testing
This page explains the fragile x carrier testing, what it measures, and how to arrange it. Fragile X carrier testing is a blood test that checks whether you carry a change in the FMR1 gene, which can be passed to children. It is usually ordered when there is a family history of fragile X syndrome, intellectual disability, or certain reproductive concerns.
- Sample type
- blood
- Category
- General Wellness
- Turnaround
- 1-3 business days
- Price
- $399
- Referral
- Not required
Fragile X carrier testing is a blood test that checks whether you carry a change in the FMR1 gene, which can be passed to children. It is usually ordered when there is a family history of fragile X syndrome, intellectual disability, or certain reproductive concerns.
What it measures
- FMR1 gene CGG repeat count — Counts a repeated DNA segment; a higher count can mean a carrier or affected status.
- Repeat size category — Places the count into normal, intermediate, premutation, or full mutation ranges.
- AGG interruptions — Small breaks in the repeat pattern that can affect how likely the repeat is to expand.
- Methylation status — Checks whether the gene is switched off, which matters mainly for full mutations.
Who it is for
A clinician may order this test if you have a family history of fragile X syndrome, unexplained intellectual disability, or fertility or reproductive concerns. It can be ordered for women and men.
Preparation
No fasting or special timing is needed. Tell your clinician about any blood thinners or bleeding conditions before the blood draw.
Results and what they mean
Results are reported as the repeat count and its category, sometimes with AGG interruption and methylation details. A clinician interprets these results in the context of your health and family history. This is general information, not medical advice.
How to order this test
- Choose the test and place a confidential order online.
- Select a certified collection site and pick a time that suits you.
- Have your specimen collected — most draws take only a few minutes.
- Review results in a secure portal, typically within 1–3 days.
Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.
Availability by state
Direct-access online ordering for the fragile x carrier testing is available in most states. It is currently unavailable in 6 states:
Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →
Frequently asked questions
Is fragile X carrier testing the same as fragile X syndrome testing?
It uses the same gene test, but carrier testing looks at whether you carry a gene change that could be passed on, rather than diagnosing symptoms.
Do I need this test if no one in my family has fragile X?
Not usually. It is most often ordered when there is a family history or a related health or reproductive concern.
How long do results take?
Typical turnaround is 1 to 3 business days, though some labs may take longer.
Will my insurance cover it?
Coverage varies by plan and reason for testing. Check with your insurer or the lab before testing.