[Principle symptoms of delayed language development and behavioral disorders. 2 case studies on the topic of fragile X syndrome].

Case reports of two boys (5 1/2 and 3 1/2 years old) with fragile X syndrome are presented. In both cases, the typical somatic signs were absent. On the other hand, the psychopathology, with delayed language development and behaviour problems (especially hyperactivity and autistic behavior), provided the indication for a chromosome analysis. Fragile X syndrome was diagnosed in both cases, but in case 2 two subsequent controls were negative. The conclusions are that a diagnosis of fragile X syndrome must be viewed with skepticism until it has been confirmed by a second chromosome analysis in another experienced laboratory and/or with a different laboratory method. In spite of the genetic etiology (case 1), a marked improvement in the symptoms was possible with an intensive remedial program. Hence the fragile X chromosome appears to predispose to certain psychopathological changes, and these changes are apparently strongly influenced by psychosocial factors. Awareness of the genetic diagnosis can have positive effects on a family's compliance concerning further therapeutic programs for the child.