Genetic Disorders

X-Fragile  Pre-FRAXA

The Fragile X syndrome is the the most frequent cause of inherited mental retardation. Normally, the FMR1 gene located on chromosome X, contains a region of 6 to 40 repeats of the CGG codon. A gene with 61 to 200 repetitions is considered a premutation and a gene with more than 200 repeats is considered a full mutation. The expansion of this region at these levels results in gene methylation, which prevents the expression of the FMR1 protein, causing X-Fragile syndorme.

Our kit allows the researcher to determine if the number of CGG repeats in the FMR1 gene is in the normal range. The test has 100% sensitivity in men. In women, a negative result indicates a normal homocygote or an heterocygote with a normal allele and a Fragile X allele.