Screening for the fragile X syndrome among the mentally retarded: a clinical study. The Collaborative Fragile X Study Group.

The fragile X syndrome is characterised by mental retardation with other features such as a long face with large, protruding ears, macro-orchidism, and eye gaze avoidance. This X linked disorder is caused by an expanded CGG repeat in the first exon of the fragile X mental retardation (FMR1) gene which is associated with shut down of transcription and absence of the fragile X mental retardation protein (FMRP). Molecular testing is used for detection of patients and carriers of the fragile X syndrome.

Screening and diagnosis for the fragile X syndrome among the mentally retarded: an epidemiological and psychological survey. Collaborative Fragile X Study Group.

The fragile X syndrome is an X-linked mental retardation disorder caused by an expanded CGG repeat in the first exon of the fragile X mental retardation (FMR1) gene. Its frequency, X-linked inheritance, and consequences for relatives all prompt for diagnosis of this disorder on a large scale in all affected individuals. A screening for the fragile X syndrome has been conducted in a representative sample of 3,352 individuals in schools and institutes for the mentally retarded in the southwestern Netherlands, by use of a brief physical examination and the DNA test.