PMS2 (postmeiotic segregation increased 2 [S. cerevisiae]) (eg, hereditary non-polyposis colorectal cancer, Lynch syndrome) gene analysis; duplication/deletion variants
CPT4 code
Name of the Procedure:
PMS2 (postmeiotic segregation increased 2 [S. cerevisiae]) gene analysis; duplication/deletion variants
Summary
The PMS2 gene analysis procedure is a genetic test that looks for duplication or deletion mutations in the PMS2 gene. This gene is important for DNA repair, and mutations can increase the risk of hereditary non-polyposis colorectal cancer, also known as Lynch syndrome.
Purpose
The test is designed to identify genetic mutations in the PMS2 gene that may lead to Lynch syndrome, a condition that significantly increases the risk of colorectal and other types of cancer. The goal is to determine if an individual carries these mutations to inform medical management and preventive care strategies.
Indications
- Family history of Lynch syndrome or related cancers.
- Early-onset colorectal cancer (typically before age 50).
- Multiple primary cancers in a single individual, especially if they include colorectal cancer.
- Family members of individuals diagnosed with Lynch syndrome.
Preparation
- Typically, no special preparation is required, but patients may be advised to avoid certain medications that could interfere with DNA sequencing.
- A detailed family history and genetic counseling session are recommended to assess risk and understand implications.
Procedure Description
- Sample Collection: A blood sample or buccal swab is collected from the patient.
- DNA Extraction: DNA is extracted from the sample in a laboratory setting.
- Genetic Analysis: The DNA is analyzed using techniques like Multiplex Ligation-dependent Probe Amplification (MLPA) to detect duplications or deletions in the PMS2 gene.
- Result Interpretation: A genetic counselor or medical geneticist interprets the findings and discusses them with the patient.
Duration
The entire process from sample collection to receiving results typically takes 2-4 weeks.
Setting
The sample collection can be done in a clinic, doctor's office, or at home (if using a mail-in kit). The analysis is performed in a specialized laboratory.
Personnel
- Genetic counselors
- Laboratory technicians
- Medical geneticists
Risks and Complications
- Minimal Risks: The procedure is minimally invasive, typically involving only a blood draw or a cheek swab.
- Psychological Impact: Receiving genetic information may be emotionally challenging.
Benefits
- Early Detection: Identifies individuals at risk for Lynch syndrome, enabling early and more frequent cancer screenings.
- Informed Decisions: Helps in making informed choices about preventive measures, such as lifestyle modifications, medications, or surgery.
Recovery
- Immediate: No physical recovery is needed.
- Follow-Up: Genetic counseling to discuss test results and implications. Regular follow-up may be recommended based on results.
Alternatives
- Other Genetic Tests: Comprehensive panels that include multiple genes associated with hereditary cancer syndromes.
- Regular Screening: Traditional cancer screening methods without genetic analysis.
- Pros and Cons: Genetic testing can provide more precise risk assessment but may not be necessary for everyone.
Patient Experience
- During Procedure: Minor discomfort from blood draw, if applicable.
- After Procedure: Patients may feel anxious while waiting for results. Genetic counseling provides support and clarity.
Effective pain management and comfort measures are incorporated throughout to ensure a positive experience.