Mountain West · Fragile X Carrier Testing – Carrier Screen
Fragile X Carrier Testing – Carrier Screen in Colorado
This page explains the fragile x carrier testing – carrier screen, what it measures, and how to order it. This test checks whether a person carries a genetic change linked to fragile X syndrome, a common inherited cause of intellectual disability.
Lab requirements in Colorado
Here is what you need before ordering and completing the Fragile X Carrier Testing – Carrier Screen in CO. Review each item and confirm the details with the collection lab.
- Physician's order
- Included. A physician's order is required for lab testing and is provided for you by our partner's physicians — no referral from your own doctor is needed.
- Fasting
- Some tests require fasting or avoiding certain foods or drinks beforehand. You will be informed when you order — confirm the details with the collection lab.
- Preparation
- No special preparation is usually needed for a blood draw. Follow the specific instructions provided by the collection laboratory or your clinician.
- Sample & visit
- A blood and/or urine sample is collected; the visit usually takes about 10 minutes.
- Identification
- Bring the lab requisition form from your account. The collection lab may also ask for a government-issued photo ID.
- Turnaround
- 1-3 business days
- Availability
- Our partner lab does not serve ND, RI, NY, NJ, MD or HI. Confirm availability for your location with the collection lab.
Before you go
- Order your test before visiting a lab, then use the requisition form in your account.
- Print the requisition form, or fax it to the lab directly from your account.
- No scheduling is needed — visit the collection lab during its normal business hours.
- A blood and/or urine sample is collected; the visit usually takes about 10 minutes.
- Bring a government-issued photo ID in case the lab requests it.
- Results are posted to your secure account within 1–3 business days.
Requirements are summarized from our partner lab's published policies. Preparation and availability can change — confirm current instructions with the collection lab before your visit.
What this test is
Fragile X carrier testing examines a specific gene on the X chromosome to see if there is an expansion in a repeated section of DNA. People with a smaller expansion are called carriers and usually do not have symptoms, but they can pass the condition to their children. This test is different from testing a fetus or a child for the full condition.
What it measures
- FMR1 gene repeat size — Reflects the number of CGG repeats, which determines carrier status and risk
- Methylation status — Sometimes assessed to understand gene activity, though not always part of carrier testing
What the test involves
A blood sample is collected from a vein in the arm using a standard blood draw. The sample is then sent to a laboratory for genetic analysis.
Why it is often ordered
A clinician may order this test for someone with a family history of fragile X syndrome, intellectual disability, or unexplained developmental delays. It is also offered to people who are planning a pregnancy or are already pregnant and want to know their carrier status.
Preparation
No special preparation is usually needed for a blood draw. Follow the specific instructions provided by the collection laboratory or your clinician.
How results are reported
Results are reported as either carrier or not a carrier, based on the size of the genetic repeat. Reference ranges and reporting methods can vary between laboratories, so your clinician will interpret your result in the context of your personal and family history.
Before you go
- Whether any special preparation is needed before the blood draw
- How long results usually take at the specific laboratory
- Whether genetic counseling is recommended before or after testing
Cities
Fragile X Carrier Testing – Carrier Screen in Colorado communities
Choose your city for local context and to order this test.