Metaphase FISH Examples
This is an example of a metaphase cell that has been hybridized with the probe for DiGeorge/Velo-Cardio-Facial/CATCH 22/Shprintzen Syndrome which is caused by a microdeletion on chromosome 22. The probe in this particular case is a dual-color mixture of two seperate probes for chromosome 22. The green signal is an internal control and is located at 22q13. It allows for quick identification of both #22 chromosomes. The red signal is located at the DiGeorge region at 22q11.2. Since both 22's have the red signal in this cell there is not a microdeletion within the DiGeorge region and this individual would not have DiGeorge Syndrome.
This metaphase has been hybridized with a "painting" probe for chromosome 4 which causes the entire chromosome to fluoresce. One chromosome 4 from this individual was abnormal but it was difficult to determine from routine Cytogenetics if it had a small terminal deletion at 4q or was the result of a more complex rearrangement. Since both 4's are fluorescent along their entire length and no fluorescent material is present on any other chromosome, this suggests that the abnormality is a small terminal deletion. The metaphase below is from the same individual and further confirms this diagnosis.
This metaphase from the same individual as the cell above has been hybridized with a probe for the terminal part of chromosome 4q. Since there is only one green signal this confirms that one chromosome 4 is missing material from the terminal end of 4q. This case is a good example of how routine Cytogenetics and FISH can be used together to accurately diagnose subtle chromosome abnormalities.
This is an example of a metaphase cell that has been hybridized with the probe for Steroid Sulfatase Deficiency which is caused by a microdeletion on the X chromosome. The probe in this particular case is a mixture of two seperate probes for the X chromosome, both red in color. The "X cen" probe signal is an internal control and is located at the X centromere. It allows for quick identification of the X chromosome(s). The "Xp22.3" probe signal is located at the Steroid Sulfatase region at Xp22.3. Since there are two X chromosomes and only one has the Steroid Sulfatase gene signal, this individual is a female carrier for Steroid Sulfatase Deficiency.
Back to FISH Information