Molecular analysis of fragile X syndrome in Antalya Province.

ABSTRACT

BACKGROUND: Detection of the (CGG)n repeats in the FMR1 gene that cause the fragile X syndrome (FXS), has become a milestone for phenotype-genotype correlation in FXS. AIMS: To screen the FMR1 gene CGG repeats in index cases with FXS and their family members in the Antalya Province. SETTING AND DESIGN: This study was prospectively conducted between January 2000 and March 2005 in Department of Medical Biology and Genetics, Faculty of Medicine, Akdeniz University, Antalya. MATERIALS AND METHODS: A series of 132 cases from three hospitals in Antalya Province were studied. All cases were molecularly screened using non-radioactive Expand Long PCR method that was confirmed by Southern blotting. RESULTS: Seventeen out of 132 cases were found to have a full mutation, including three that were mosaic for premutations/full mutations. Of the 132 cases, eight were found to have the premutation size of the CGG repeats. The remaining 107 cases were identified as normal. CONCLUSIONS: Due to premature ovarian failure and Fragile X premutation Tremor/Ataxia Syndrome related with the premutation, the detection of the premutation will provide valuable information both for clinical follow-up and genetic counseling. In conclusion, our data suggest that expansion of CGG repeats in the FMR1 gene can be analyzed by Expand Long PCR, an efficient and non-radioactive method that can be used to monitor the expansion of premutation to full mutation, which would eventually lead to reduce the FXS prevalence.