Williams syndrome : (7q11.23) FISH Analysis

Test Information

Cytogenetic FISH analysis for Williams syndrome (7q11.23). FISH is also utilized to confirm microdeletions identified during high resolution chromosome analysis.

Turnaround Time

4 weeks

CPT Code(s)

88275, 88273, 88271, 88291=Modifier 22

Cost

$584


Chromosomes

7q11.23

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, including blood, fibroblasts, amniotic fluid, and chorionic villus sampling. Follow collection and transport guidelines specific for each tissue type. Studies requested should be indicated at the time of sample submission.

Transport Instructions

Will vary depending on sample type:
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.

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Cytogenetic Testing, FISH
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One Mother's Story

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