The common fragile site in band q27 of the human X chromosome is not coincident with the fragile X.
The common fragile site on the end of the long arm of the human X chromosome has been shown to be at a different location from the rare fragile site which produces the fragile X syndrome of intellectual handicap. The different locations can be clearly seen in chromosomes at about the 550 band level of resolution. This finding should help resolve difficulties in fragile X cytogenetics where expression of the common fragile site can lead to false positive diagnoses.
Sutherland
G R
GR
Department of Histopathology, Adelaide Children's Hospital, Australia.
Baker
E
E
D002871:Chromosome Banding; D043283:Chromosome Fragile Sites; D002873:Chromosome Fragility; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005600:Fragile X Syndrome / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D008297:Male; D012729:Sex Chromosome Aberrations / Q000235:genetics*; D014960:X Chromosome