Since the discovery of the Fragile X syndrome some 20 years ago, there
have been numerous articles concerning clinical features, cognitive p
rofile and transmission. It is a syndrome of importance to all those w
orking in the mental health field and those involved in community heal
th, such as General Practitioners, since it is second only to Down syn
drome as a genetic cause of mental handicap. In this article we review
the literature pertaining to Fragile X and present two typical cases
of the syndrome.