Amyotrophic lateral sclerosis in a patient with fragile X syndrome.

Fragile X syndrome is a common cause of mental retardation. We report the clinical and pathologic features of a patient with fragile X syndrome who developed amyotrophic lateral sclerosis (ALS) at a relatively young age. Although the occurrence of these 2 diseases could be a mere coincidence, the development of ALS in this patient might be related to the chromosomal aberration of fragile X syndrome.