FISH for Congenital Anomalies
|Clinical info||A number of genetic syndromes are caused by the deletion of a small region of a particular chromosome. Each syndrome has unique phenotype of specific structural birth defects, dysmorphic featuers, developmental delays, and other potential medical issues. Often these deletions are too small to be picked up by standard or high resolution chromosome analysis, in which case, microdeletion syndrome probes must be used to elucidate the chromosome abnormality. Probes for the following disorders are available:
|Indications||Fluorescence in situ hybridization is a molecular cytogenetic technique in which fluorescently labeled DNA probes are hybridized to metaphase spreads or interphase nuclei. Applications include identification of structurally abnormal chromosomes, including identification of marker chromosomes, detection of very small deletions (microdeletions), and rapid detection of Down syndrome and other numerical chromosome abnormalities; and the rapid detection of sex chromosomes and the SRY gene. FISH should be used in conjunction with G-banded chromosome analysis. FISH is performed upon request when a specific numerical or structural abnormality or microdeletion is suspected. FISH is also utilized to confirm microdeletions identified during high resolution chromosome analysis and to aid in identification of abnormal chromosomes.|
|Specimen Requirements||FISH can be performed on any tissue that can be cultured for chromosome analysis and interphase FISH can be performed on any cytogenetic sample. Follow collection and transport guidelines specific for each tissue type. Studies requested should be indicated at the time of sample submission.|
|Transport||Will vary depending on sample type (see below)
Blood: Specimen should be kept at room temperature; do not freeze or refrigerate. Specimen should be sent by courier or overnight mail to arrive at the laboratory within 24 hours
Amniotic Fluid and CVS: Specimen should be kept at room temperature; do not freeze or refrigerate. Specimen should be sent by courier or overnight mail to arrive at the laboratory within 24 hours.
Solid Tissue(such as skin biopsy, products of conception, or abortus tissue): Specimen should be kept at room temperature if it will be transported immediately. If specimen is not being immediately transported to the laboratory, it may be refrigerated; do not freeze. Specimen should be sent by courier or overnight mail to arrive at the laboratory within 24 hours.
|Turnaround time||28 days for specific FISH probes for peripheral bloods, tissues, amniotic fluid, and CVS
24-48 hours for AneuVysion (Trisomy Screen). The weekend may extend this turnaround time up to 4 days, and the costs listed below include a STAT fee of $50.
|CPT Codes||88274, 88271, 88273, 88291
*these tests use only 88274, 88271, 88291
Trisomy Screen: 88235, 88275, 88271x4, 88291
The Cytogenetics Lab provides high quality analysis for the detection of both constitutional chromosomal aberrations as well as abnormalities related to hematological malignancies