FISH Analysis - DiGeorge/Velocardiofacial Syndrome Panel (22q and 10p)
Use
The FISH Analysis for DiGeorge/Velocardiofacial Syndrome is an essential diagnostic tool aimed at detecting chromosomal deletions located at 22q11 and 10p13-p14 associated with DiGeorge Syndrome, a condition characterized by diverse clinical manifestations such as congenital cardiac defects, developmental delays, and palatal abnormalities. The test is particularly indicated for patients exhibiting clinical signs typical of DiGeorge Syndrome, including conotruncal cardiac anomalies and other suggestive features. Given the variability of the disorder, confirming the presence of critical chromosomal deletions aids in patient management and genetic counseling, reinforcing the importance of earlier diagnosis through timely testing.
Special Instructions
Initial screening with Chromosome Microarray Analysis (test code 8655) is advised. The assay is susceptible to variations, and results should be interpreted in conjunction with clinical findings. For better accuracy and reliability, clinicians are encouraged to refer patients exhibiting signs of DiGeorge Syndrome for testing. Specimen collection and shipping should adhere strictly to the guidelines provided. Annotations regarding the inherited nature of the syndrome clarify its autosomal dominant transmission pattern.
Limitations
The FISH assay focuses solely on detecting gains or losses of specified genes, meaning a normal FISH result may not rule out the presence of structural rearrangements. Therefore, it is crucial for patients suspected of having DiGeorge Syndrome to also consider Chromosomal Microarray testing for a comprehensive evaluation. Essentially, a normal result does not eliminate the possibility of other genetic conditions that might resemble or overlap with DiGeorge Syndrome.
Methodology
Chromosomal / Cytogenetics (FISH)
Biomarkers
Result Turnaround Time
14 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood (Unknown)
Volume
3-5 cc (Adults/Children) or 1-2 cc (Infants <2 years)
Minimum Volume
3-5 cc (Adults/Children) or 1-2 cc (Infants <2 years)
Container
Sodium Heparin tube
Collection Instructions
Draw blood in a Sodium Heparin (green-top) tube(s) and send as per volume requirements.
Storage Instructions
Ship the sample at room temperature; specification cannot be frozen.
Causes for Rejection
EDTA and plasma separator tubes (PST) are not acceptable for cytogenetic analysis.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
Other tests from different labs that may be relevant