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Test Code CGSNPP CYTOGENOMIC SNP ARRAY, CONGENITAL DISORDERS, AMNIOTIC FLUID

Important Note

Please call the lab at 2-6203 for any ordering questions and for sample pick up.

SNP Array and Chromosome Analysis are done concurrently, but are ordered separately.

Specimen and Container/Tube

Amniotic fluid collected in sterile 15ml conical tubes (provided by the laboratory)

Please DO NOT use AMBER TUBES.  These can be toxic to amniotic fluid cells.

Specimen Handling and Transport Instructions

Once the specimen is collected, the laboratory should be called at 2-6203 for sample pickup.  AF specimens should NOT be tubed!

Rejection Criteria

>72 hours after collection

Reference Values

Interpretative Report

Critical Values

N/A

Turnaround Time

N/A

CPT Codes

88235;  81229

LOINC Codes

N/A

Volume

35 mL Preferred:  12-15mL for SNP Array + 10-20mL for Chromosme Analysis

Collection Instructions

Amniotic fluid should be collected in sterile 15mL conical tubes (provided by the lab).  Keep at room temperature.   If specimen will sit for more than 24 hrs, please refrigerate at 4°C until specimen can be picked up by the laboratory

Last Review Date

11/14/2022 RB

Additional Information

SNP Array Test Limitations:  Will not detect balanced translocations, low level mosaicism,
some instances of uiparental disomy, point mutations and small insertion/deletions.

Clinical Indications

Indication for prenatal SNP array include: pregnancies at increased risk for fetal chromosome abnormality based on maternal age, abnormal noninvasive prenatal testing (NIPT), abnormal multiple marker screening, or abnormal fetal ultrasound; clarification of ambiguous chromosome results; family history of genetic syndrome of unknown etiology.

Test Components

This array includes 2.67 million markers for copy number (CN) analysis including approximately 750,000 SNP probes, and 1.9 million non-polymorphic probes for whole genome coverage.

Methodology

SNP Microarray

Synonyms/Key Search Words

Microarray, SNP, gen hyb, ACGH, Gene, Whole Gene, CGH

Specimen Stability

Keep at room temperature and deliver to the lab within 24 hours.  If specimen will sit for more than 24 hrs, please refrigerate at 4°C until specimen can be picked up by the laboratory