Prenatal Fragile X Syndrome (FMR1 repeat analysis)
Use
This test enables prenatal diagnosis of Fragile X Syndrome by determining the CGG repeat size and methylation status of the FMR1 gene in fetal samples (e.g., amniotic fluid, chorionic villus sampling). It assists in early detection of full mutations (>200 CGG repeats) that result in Fragile X Syndrome, providing critical information for parental counseling and pregnancy management.
Special Instructions
Order requires appropriate fetal specimen (amniotic fluid, chorionic villi). Maternal and paternal samples may be required to assess maternal cell contamination and for familial interpretation via reflex testing (e.g., Southern blot if PCR indicates full mutation).
Limitations
PCR may detect CGG repeat expansions up to a certain size, but full mutations and methylation status often require Southern blot confirmation. Mosaicism or borderline repeat sizes may reduce diagnostic clarity. Prenatal samples may have technical artifacts affecting methylation interpretation.
Methodology
PCR-based (PCR)
Biomarkers
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
Specimen
Amniotic Fluid
Volume
Not provided
Minimum Volume
Not provided