Serum matrix metalloproteinase-9 (MMP9) and amyloid-beta protein precursor (APP) as potential biomarkers in children with Fragile-X syndrome: A cross sectional study.

Introduction: Fragile-X syndrome(FXS) is a neurological disease caused by abnormal repeats in the 5'untranslated region of the FMR1 gene leading to a defective fragile-X-messenger-ribonucleoprotein-1 (FMRP). Although relatively common in children, it is usually under-diagnosed especially in developing countries where genetic screening is not routinely practiced. So far, FXS lacks a laboratory biomarker that can be used for screening, severity scoring or therapeutic monitoring of potential new treatments.