How severely a person is affected by fragile X syndrome depends primarily on whether their fragile X mental retardation 1 (FMR1) gene is partially turned off (partially methylated) or fully turned off (fully methylated) and how much fragile X mental retardation protein (FMRP) their body is making. The less protein present in the body and brain, the more severely affected they will be since this protein plays a crucial role in the development of the nerve cells and their connections. External environmental factors (for example, diet, exercise, etc.) will not affect the severity of fragile X syndrome. Early diagnosis of fragile x syndrome can allow for early intervention that may improve quality of life; these interventions may include speech therapy, special education, psychotherapy, and more. For more information about early intervention, please visit the Center for Parent Information and Resources.