Maple Syrup Urine Disease (MSUD) Mutation Analysis (Ashkenazi Jewish)

Test Code
90909

CPT Codes
81205

Preferred Specimen
4 mL whole blood collected in an EDTA (lavender-top) tube

Minimum Volume
3 mL

Other Acceptable Specimens
Whole blood collected in: EDTA (royal blue-top), sodium heparin (green-top), ACD solution B (yellow-top), ACD solution A (yellow-top) or lithium heparin (green-top) • Amniotic fluid • Amniocyte culture • Chorionic villus sampling

Instructions
Whole blood (preferred): Normal phlebotomy procedure. Specimen stability is crucial. Store and ship room temperature immediately. Do not freeze. For prenatal diagnosis with a fetal specimen: 1) parents must be documented carriers of one of the mutations tested; 2) maternal blood or DNA must be available; 3) contact the laboratory genetic counselor before submission.

Amniotic fluid (acceptable): Normal collection procedure. Specimen stability is crucial. Store and ship room temperature immediately. Do not refrigerate or freeze.

Amniocyte culture (acceptable): Sterile T25 flask, filled with culture medium. Specimen stability is crucial. Store and ship room temperature immediately. Do not refrigerate or freeze.

Dissected chorionic villus (CVS) biopsy (acceptable): 10-20 mg dissected chorionic villi collected in sterile tube filled with sterile culture media. Specimen stability is crucial. Store and ship room temperature immediately. Do not refrigerate or freeze.
Forward cells to laboratory immediately.

Transport Temperature
Room temperature

Specimen Stability
Whole blood (preferred)
Room temperature: 8 days
Refrigerated: 8 days
Frozen: Unacceptable
Amniotic Fluid
Room temperature: 8 hours
Refrigerated: Unacceptable
Frozen: Unacceptable
Amniotic Cultured cells/chorionic villi
Room temperature: 48 hours
Refrigerated: Unacceptable
Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Wrong test indication • Whole blood received frozen 

Methodology
Polymerase Chain Reaction (PCR) • Next Generation Sequencing

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: Mon, Sat; Report available: 11-17 days

Reference Range
See Laboratory Report

Clinical Significance
1. To identify disease-causing mutations in Ashkenazi-Jewish individuals affected with Maple Syrup Urine Disease (MSUD).
2. To identify carriers in the Ashkenazi-Jewish population or in individuals with a positive family history.
3. Prenatal diagnosis of Maple Syrup Urine Disease in at-risk couples.

Performing Laboratory
Quest Diagnostics Nichols Inst San Juan Capistrano
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.