Diagnosis of fragile X syndrome

Abstract

Fragile X syndrome accounts for between one third and one half of all X-linked mental retardation. It is the most common cause of familial intellectual handicap and is second in prevalence only to Down’s syndrome among the mental retardations. The syndrome is known to affect about 1 in 2500 males and a similar number of females. It has been detected in all ethnic groups with access to modern medicine. The economic and social costs of this disorder made the determination of its molecular basis a high priority.