Automatic detection of fragile X chromosomes using an X centromere probe.
In order to score for the fragile X syndrome, blood samples are prepared with absorption stain labeling by in situ hybridisation of the X chromosome centromeres. Metaphases are located, digitised at high resolution, and segmented fully automatically. A three stage adaptive classification scheme for labeled X chromosomes is then applied. This consists of a simple box classifier to identify plausible X and false positive X chromosomes, followed by a quadratic discriminant classifier that is re-trained for each sample. The modal number of X chromosomes is then determined for each sample and used to refine the classification. A simple fragile site detector is applied to the distal portion of the detected X chromosome long arms. From the results we estimate computer and operator time requirements for a screening system in which the operator reviews only the apparently fragile X chromosomes detected by the computer.
Piper
J
J
MRC Human Genetics Unit, Edinburgh, Scotland.
Fantes
J
J
Gosden
J
J
Ji
L A
LA
D001710:Biotin / Q000031:analogs & derivatives; D002503:Centromere / Q000032:analysis*; D002875:Chromosomes / Q000032:analysis*; D004276:DNA, Satellite / Q000032:analysis; D005260:Female; D005600:Fragile X Syndrome / Q000175:diagnosis*; D006735:Horseradish Peroxidase; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009693:Nucleic Acid Hybridization; D015341:Nucleic Acid Probes; D012729:Sex Chromosome Aberrations / Q000175:diagnosis*; D012730:Sex Chromosomes / Q000032:analysis; D014960:X Chromosome / Q000648:ultrastructure*
D004276:DNA, Satellite; D015341:Nucleic Acid Probes; D001710:Biotin; D006735:Horseradish Peroxidase