CPT® Code 81293

Official Description

MLH1 (mutL homolog 1, colon cancer, nonpolyposis type 2) (eg, hereditary non-polyposis colorectal cancer, Lynch syndrome) gene analysis; known familial variants

Common Language Description

The CPT® Code 81293 pertains to the molecular genetic testing of the MLH1 gene, specifically focusing on known familial variants associated with hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome. This testing is crucial for identifying specific mutations within the MLH1 gene that significantly increase an individual's risk of developing colorectal cancer and other related malignancies. The MLH1 gene, located on chromosome 3, plays a vital role in encoding proteins responsible for DNA repair. When mutations occur in this gene, they can either prevent the production of the MLH1 protein or alter its structure, rendering it ineffective in repairing DNA errors. Over time, these unrepaired errors can accumulate, leading to uncontrolled cell proliferation and the formation of tumors. HNPCC is the most prevalent cancer type linked to MLH1 mutations, but the implications of these mutations extend beyond colorectal cancer. Individuals with MLH1 mutations may also face an increased risk of developing cancers in various organs, including the endometrium, ovaries, prostate, stomach, small intestine, liver, gallbladder duct, upper urinary tract, brain, and skin. The identification of these mutations is particularly important for family members of affected individuals, as they may also carry the same genetic risk. The testing process involves analyzing known familial variants to assess the likelihood of these mutations being present in relatives, thereby aiding in the determination of their cancer risk. This targeted approach to genetic testing is essential for effective cancer risk management and prevention strategies within families affected by Lynch syndrome.

1. Indications

The molecular genetic testing for the MLH1 gene is indicated for individuals who have a family history of hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome. This testing is particularly relevant for:

Family History of HNPCC: Individuals with a known familial history of Lynch syndrome or related cancers.
Identified MLH1 Mutation: Family members of individuals who have been previously identified with an MLH1 gene mutation.
Increased Cancer Risk: Individuals who may be at increased risk of developing colorectal cancer and other associated malignancies due to genetic predisposition.

2. Procedure

The procedure for conducting the MLH1 gene analysis for known familial variants involves several key steps:

Sample Collection: A biological sample, typically blood or saliva, is collected from the individual undergoing testing. This sample contains the DNA necessary for analysis.
DNA Extraction: The DNA is extracted from the collected sample using standard laboratory techniques to isolate the genetic material for further analysis.
Genetic Analysis: The extracted DNA is subjected to molecular genetic testing specifically designed to identify known familial variants in the MLH1 gene. This may involve techniques such as polymerase chain reaction (PCR) and sequencing to detect specific mutations.
Data Interpretation: The results of the genetic analysis are interpreted by qualified geneticists or laboratory professionals. They assess whether the identified variants are associated with an increased risk of cancer based on existing familial data.
Reporting Results: A comprehensive report is generated, detailing the findings of the analysis, including any identified familial variants and their implications for cancer risk in the individual and their relatives.

3. Post-Procedure

After the MLH1 gene analysis is completed, individuals may receive genetic counseling to discuss the results and their implications. This counseling is essential for understanding the potential risks for the individual and their family members. If a known familial variant is identified, family members may be encouraged to undergo testing to assess their own risk. Additionally, individuals may be advised on appropriate cancer screening and prevention strategies based on their genetic risk profile. Follow-up appointments may be scheduled to monitor any health changes and to provide ongoing support and information regarding cancer risk management.

Short Descr	MLH1 GENE KNOWN VARIANTS
Medium Descr	MLH1 GENE ANALYSIS KNOWN FAMILIAL VARIANTS
Long Descr	MLH1 (mutL homolog 1, colon cancer, nonpolyposis type 2) (eg, hereditary non-polyposis colorectal cancer, Lynch syndrome) gene analysis; known familial variants
Status Code	Statutory Exclusion (from MPFS, may be paid under other methodologies)
Global Days	XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC)	9 - Not Applicable
Multiple Procedures (51)	9 - Concept does not apply.
Bilateral Surgery (50)	9 - Concept does not apply.
Physician Supervisions	09 - Concept does not apply.
Assistant Surgeon (80, 82)	9 - Concept does not apply.
Co-Surgeons (62)	9 - Concept does not apply.
Team Surgery (66)	9 - Concept does not apply.
Diagnostic Imaging Family	99 - Concept Does Not Apply
CLIA Waived (QW)	No
APC Status Indicator	Service Paid under Fee Schedule or Payment System other than OPPS
Type of Service (TOS)	5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS)	T1H - Lab tests - other (non-Medicare fee schedule)
MUE	1
CCS Clinical Classification	234 - Pathology