CHROMOSOME ANALYSIS WITH FLUORESCENCE IN SITU HYBRIDIZATION TEST FOR MICRODELETION SYNDROME

Lab Section Category	Cytogenetics - PP FISH View write-up
Specimen Required	Peripheral Blood/Amniotic Fluid/Chorionic Villi
Indications	This test is useful for patients suspected of Di-George (DGS) syndrome.
Method	Long-term culture to obtain metaphases. Di-George region DNA probe labelled with fluorophores are used on interphase cells and metaphases. Analysis is performed under fluorescence microscope.
Test Results	Deleted or Not Deleted or Duplicated. Nomenclature given is in accordance to the International System for Human Cytogenomic Nomenclature (ISCN, 2024). Concurrent interphase FISH will detect duplication of that gene of interest.
Reference Interval / Value	Individuals with a microdeletion will show two copies of the internal control signals but only one copy of the locus-specific signal for that region of interest.
Turnaround Time	8 ~ 12 days
Day(s) Test Set up	Monday – Saturday (office hours)
Remarks	This FISH test is always used in conjunction with conventional cytogenetic studies. Contact the Cytogenetics Laboratory before sending a specimen.

Change History Notes

21 Oct 2025 11:19 AM

Updated test results for ISCN, 2020 to ISCN, 2024
15 Oct 2024 03:30 PM

FISH probes for Prader-Willi (PWS)/Angelman (AS) and Williams-Beuren (WBS) syndromes are not available.
11 May 2022 04:25 PM

Updated Indications: from William (WS) syndromes to Williams-Beuren (WBS) syndromes
11 May 2022 04:25 PM

Updated the test result from ISCN, 2016 to ISCN, 2020
06 Jul 2017 10:50 AM

Updated the test result for ISCN, 2013 to ISCN, 2016
08 Dec 2015 08:30 AM

Updated Turnaround Time: 8 ~ 12 days

Last Updated - 21 Oct 2025

CHROMOSOME ANALYSIS WITH FLUORESCENCE IN SITU HYBRIDIZATION TEST FOR MICRODELETION SYNDROMES