[FROM GENETICS OF FRAGILE X SYNDROME TO DEVELOPMENT OF TARGETED AND PERSONALIZED DRUG THERAPY].

At the end of the last century Fragile X syndrome was identified, and the main syndrome characteristics were discovered. The syndrome is caused from a flaw in the number of nucleotide repeats that encodes for a regulatory protein which is critical for neural connectivity and normal brain development. The syndrome is characterized by neurodevelopmental and intellectual disabilities, autism spectrum features and other clinical features associated with the same gene aberration. The number of trinucleotide repeats have a direct effect on the outcome and the need for genetic counseling. We advocate performing genetic tests for every child with developmental delay, learning disabilities, autism spectrum disorders and especially, intellectual impairment. It is also advisable to check the number of nucleotide repeats of the gene, in every woman suffering from infertility or early menopause. In addition, genetic testing should be performed on older adults manifesting early symptoms of Parkinson's disease, balance instability, tremor or cognitive dysfunction with unknown etiology. Due to the tremendous progress in understanding the biological mechanisms of the syndrome, new molecules/drugs have been proposed and are tested, in order to find a way to bypass the defect mechanism underlying the disorder. We will review the most commonly used drugs in the treatment of Fragile X syndrome and many medications that are currently under investigation as a more targeted treatment.