UT Southwestern researchers uncover fragile X syndrome gene's role

Researchers at UT Southwestern Medical Center have discovered how the genetic mutation that causes Fragile X syndrome, the most common form of inherited mental retardation, interferes with the "pruning" of nerve connections in the brain. They found Fragile X is caused by a mutation in a single gene, Fmr1, on the X chromosome. The gene codes for a protein called FMRP, which plays a role in learning and memory but whose full function is unknown. The protein's role in pruning nerve connections had been unclear.