The Fragile X Syndrome genetic test examines the length of the repeat region in the FMR1 gene. The genetic test determines if an individual has a full mutation, a premutation, an intermediate allele or a normal allele.
People with a normal number of repeats (5-44) or an intermediate number (45-54) do not have fragile X syndrome. Individuals with the premutation (55-200 repeats) may exhibit mild symptoms. The presence of a premutation can also cause fertility issues and tremors. When the repeat size exceeds 200, these patients are predicted to have fragile X syndrome.
None. This test can be taken at any age.
Buccal swabs. The test kit contains buccal swabs and instructions for collecting a buccal swab sample from inside the mouth.
Four buccal swabs, rubbed inside the mouth against the cheek for 15 seconds.
1 – 2 weeks.
Number of repeats in the FMR1 gene
Laboratory specimens are analyzed using polymerase chain reaction to determine the length of the repeat region in the FMR1 gene. Analytical specificity and sensitivity for detection of this repeat length are >99%. Other changes not listed are not detected.
DNA test kits do not have an expiry date and can be used at any time. Once the DNA sample is collected, it must be returned to the laboratory for testing within three months of collection. No refrigeration is required. Store at room temperature.
This test will only determine the length of the repeat region in the FMR1 gene. Other mutations in this gene or other genes will not be detected in this assay.
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