Thesis (Ph.D.) - Cairo University - Faculty of Medicine - Department of Clinical and Chemical Pathology

Fragile X syndrome, the most common form of inherited intellectual disability, is caused by expansion of CGG trinucleotide repeat at the 5' untranslated region of the FMR1 gene at Xq27.The main clinical features of FXS are mental retardation, macro-orchidism, long face, prominent jaw, connective tissue abnormalities, and behavioral problems. In affected individuals, the CGG repeat expansion leads to hypermethylation and the gene is transcriptionally inactive. The main clinical features of FXS are mental retardation, macro-orchidism, long face, prominent jaw, connective tissue abnormalities, and behavioral problems.The present study represents an attempt to detect expected alleles for FMR 1 gene by methylation sensitive PCR based method with clinical correlation to the molecular characterization aiming to rapid screening of fragile X syndrome among patients with intellectual disability.The study included 50 male patients with intellectual disability and clinical features suggestive of fragile X syndrome. A control group of 50 healthy age matched volunteers were also conducted. All patients were subjected to full history taking including family history and thorough clinical examination using a 15-item checklist, karyotyping using GTG banding for the detection of concomitant numerical or structural chromosomal abnormalities. Molecular diagnosis for the detection of expanded alleles of the FMR1 gene using Methylation sensitive PCR technique after bisulfite treatment of DNA was applied

Issued also as CD