Fragile X in Eastern & Southeastern Anatolia: A 2019–2025 Single-Center Cohort of 306 Male Referrals
Fragile X Syndrome
DOI:
https://doi.org/10.5281/zenodo.21263021Keywords:
Fragile X Syndrome , FMR1, Genetic Testing, Genetic CounselingAbstract
Objective: Fragile X syndrome (FXS) is a leading cause of inherited intellectual disability, yet epidemiological data from Eastern and Southeastern Türkiye remain scarce. This study aimed to determine the diagnostic yield and allele distribution of FMR1 expansions in a male cohort from these underserved regions.
Methods: We conducted a retrospective, single-center audit of 306 consecutive male referrals tested for FMR1 CGG repeats between January 2019 and August 2025. Analysis was performed using PCR-based sizing and triplet-primed PCR.
Results: The overall prevalence of FMR1 expansions was 5.2% (16/306). Full mutations (>200 repeats) were identified in 3.3% (10/306) of the cohort, all in children aged ≤11 years. Premutations (55–200 repeats) were found in 2.0% (6/306) of cases, with a notably wider age distribution extending into late adulthood. No intermediate (gray zone) alleles were detected.
Conclusion: These findings confirm a clinically significant yield for FMR1 testing in the region. The absence of gray zone alleles and the detection of older premutation carriers highlight distinct referral patterns and the critical need for family cascade screening.
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