Ordering Recommendation

Recommended test to distinguish between Lynch syndrome and sporadic noncolorectal tumors with loss of MLH1.

Mnemonic
MLH1PCR
Methodology

Real-Time Polymerase Chain Reaction/Fluorescence Resonance Energy Transfer

Performed

DNA isolation: Sun-Sat
Assay: Varies

Reported

7-12 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Tumor tissue. Also acceptable: DNA extracted by CLIA certified lab with corresponding client-circled H&E slide.

Specimen Preparation

Tumor Tissue: Formalin fix (10 percent neutral buffered formalin) and paraffin embed tissue. Protect from excessive heat. Transport tissue block or 5 unstained 5-micron slides. (Min: 3 slides) Transport block and/or slide(s) in a tissue transport kit (ARUP Supply #47808) available online through eSupply using ARUP Connect™ or contact ARUP Client Services at (800) 522-2787.
Extracted DNA: Transport 40 uL DNA with at least 50 ng/uL concentration. (Min: 40 uL) Transport DNA in a tissue transport kit (ARUP Supply #47808) available online through eSupply using ARUP Connect™ or contact ARUP Client Services at (800) 522-2787.

Storage/Transport Temperature

Room temperature. Also acceptable: Refrigerated. Ship in cooled container during summer months.
Extracted DNA: Refrigerated.

Unacceptable Conditions

Less than 25 percent tumor. DNA extracted by a non-CLIA lab. DNA extracted without a corresponding circled H&E slide. Specimens fixed/processed in alternative fixatives (alcohol, Prefer) or heavy metal fixatives (B-4 or B-5). Decalcified specimens.

Remarks

Include surgical pathology report.

Stability

Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable
Extracted DNA: Ambient: 1 month; Refrigerated: Indefinitely; Frozen: Indefinitely

Reference Interval
Interpretive Data

Refer to report.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

88381; 81288

Components
Component Test Code* Component Chart Name LOINC
0051749 MLH1 Promoter Methylation
2002148 Block ID 57723-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • HNPCC screening
  • Lynch syndrome screening
MLH1 Promoter Methylation, Paraffin