Fragile X syndrome: a common etiology of mental retardation.

Abstract

Fragile X syndrome, second only to Down syndrome among etiologies of mental retardation, was discussed. Clinical, intellectual, and anthropometric characteristics from 67 fragile X positive males, 35 fragile X positive females, and 27 obligate carriers among 29 families was presented. Regression analysis showed little correlation between level of intellect and frequency of fragile sites. The mean IQ among the various age groups of male patients decreased with increasing age, and some intellectual deterioration could not be ruled out. Folic acid was suggested as a viable treatment mode among prepubescent males.