Lab Dept:

Anatomic Pathology

Test Name:

ANIRIDIA (PAX6) COPY DX DELETION/DUPLICATION

General Information

Lab Order Codes:

PXCD (Blood samples only)

Synonyms:

Aniridia Gene Testing; Developmental Eye Disorders Gene Testing

CPT Codes:

83891 x2 – Isolation or extraction of highly purified nucleic acid
83892 x2 – Molecular diagnostics; enzymatic digestion
83898 x12 – Amplification of nucleic acid

Test Includes:

For the gene of interest, the number of copies present in the patient's sample.

Logistics

Test Indications:

Aniridia is a developmental anomaly of the entire eye, characterized by varying degrees of iris hypoplasia, foveal hypoplasia, and/or nysagmus. Frequently associated findings with onset later in life include cataracts, limbal stem cell deficiency, and glaucoma.

Applications of CopyDx gene copy number analysis:
1. As a complementary test or substitute for FISH and quantitative microarray analysis when a deletion or duplication syndrome (contiguous or single gene) is suspected.
2. As a confirmation test for a genomic gain or loss identified by genome-wide microarray analysis.
3. To determine the presence or absence of a specific gene within a deleted chromosomal segment (contiguous gene deletion).
4. Diagnostic testing in a Mendelian disorder due to functional loss of one allele (haploinsufficiency), in particular when sequence analysis failed to identify a causative mutation and a whole gene deletion is a possible cause.
5. Carrier testing for deletion/duplication syndromes when the specific region is known in an affected relative.

Lab Testing Sections:

Anatomic Pathology - Sendouts

Referred to:

GeneDx, Inc. (GDX#: 904, Specify gene/mutation)

Phone Numbers:

Minneapolis:

Saint Paul:

612-813-6280

651-220-6550

Test Availability:

Daily, 24 hours (Preferred draws are Sunday - Thursday as specimens can only be received at the reference lab Monday - Friday. Specimens collected Friday or Saturday will be held for shipment on Monday.)

Turnaround Time:

4 - 6 weeks

Special Instructions:

A GeneDx signed consent form and request form must be sent with any patient or specimen to the laboratory.

Specimen

Specimen Type:

Whole blood

Container:

Blood: Lavender top (EDTA) tube

Draw Volume:

1 - 5 mL blood

Processed Volume:

Same as Draw Volume

Collection:

Routine venipuncture for blood specimens, invert gently to mix

Special Processing:

Lab Staff: Send whole blood in original collection container labeled with patient name, date of birth and medical record number, including signed consent form and requisition, with a cool pack, via overnight or second-day courier so that the sample will arrive at GeneDx, Inc. on a weekday (Monday through Friday). Samples drawn on Friday or Saturday should be held at refrigerated temperatures for shipment on Sunday. Do not freeze.
Note: Specimens may be stored at refrigerated temperatures for up to 3 days prior to shipping.

Patient Preparation:

None

Sample Rejection:

Unrefrigerated specimens older than 48 hours, clotted or hemolyzed for blood, frozen specimens, mislabeled or unlabeled specimens

Interpretive

Reference Range:

Interpretive report

Critical Values:

N/A

Limitations:

N/A

Methodology:

Comparative quantitative analysis, fluorescent quantitative PCR-based method. Analysis done in triplicate.

References:

GeneDx, Inc. February 2008
(301) 519-2100 Fax (301) 519-2892