FRAGILE X syndrome(FMRI GENE)

The FMRI test replaced chromosome testing, and became the standard test for determining the presence of Fragile X. The most common inherited cause of mental retardation comes from the appearance of the stained X chromosome under a microscope. There is a site near the end of this chromosome that does not stain, indicating its fragility and the gene in this fragile region is important in making a certain protein needed by developing brain cells.