Fragile X Syndrome

What Causes Fragile X? In 1991, scientists discovered the gene (called FMR1) that causes fragile X. FMR1 cannot manufacture the protein that it normally makes Fragile X is inherited. A male who inherits a full mutation exhibits characteristics of Fragile X syndrome because his only X chromosome contains the mutated gene. A female may not be as severely affected as a male because each cell of her body needs to use only one of its two X chromosomes and randomly inactivates the other.

Prevalence Fragile X syndrome is the single most common inherited cause of mental impairment Fragile X affects 1 in 2000 males Fragile X affects 1 in 4000 females Approximately 40% of cases with X-linked mental retardation

Signs and Symptoms mental impairment, ranging from learning disabilities to mental retardation attention deficit and hyperactivity anxiety and unstable mood autistic-like behaviors long face, large ears, flat feet, and hyperextensible joints, especially fingers Seizures (epilepsy) affect about 25% of people with fragile X

Testing A DNA based test to diagnose Fragile X was developed in 1992 The blood test can be ordered by any physician; the blood sample is then sent to one of the labs that offers the test The test typically costs $200-$300 Southern Blot Polymerase Chain Reaction (PCR) Chromosome test Protein test

There is NO cure for Fragile X However, there are a variety of ways to help minimize the symptoms of the condition Those who receive appropriate education, behavioral or physical therapy, and medication have the best chance of using their individual capabilities and skills

Research FMR protein's normal role is to help shape the connections between neurons (brain cells) that underlie learning and memory Some questions that they are asking: Why does the FMR1 gene have an increased number of CGG repeats in the promoter region? What causes the increased methylation of the promoter region, which blocks the gene from producing FMRP? What is the role of FMRP in the brain? How does FMRP help other proteins, and what are the functions of those proteins?

Test Question What is the gene that causes Fragile X? FMR1 gene