PMS2 (postmeiotic segregation increased 2 [S. cerevisiae]) (eg, hereditary non-polyposis colorectal cancer, Lynch syndrome) gene analysis; full sequence analysis
CPT4 code
Name of the Procedure:
PMS2 (Postmeiotic Segregation Increased 2 [S. cerevisiae]) Gene Analysis; Full Sequence Analysis
Summary
This procedure involves the complete analysis of the PMS2 gene's DNA sequence. The PMS2 gene is significant because its mutations are associated with hereditary non-polyposis colorectal cancer (HNPCC), commonly known as Lynch syndrome. The analysis helps in identifying mutations that could lead to an increased risk of certain cancers.
Purpose
- Medical Condition: Hereditary non-polyposis colorectal cancer (Lynch syndrome)
- Goals: To identify mutations in the PMS2 gene which can indicate an elevated risk for colorectal and other cancers, allowing for informed decisions regarding patient management and preventive measures.
Indications
- Family history of Lynch syndrome or related cancers
- Early onset colorectal cancer or other Lynch syndrome–associated cancers
- Known family mutation in the PMS2 gene
- Unusual multiple primary cancers
Preparation
- No special preparation is typically required.
- A blood sample is usually needed for the test.
- Genetic counseling is recommended before and after the procedure to discuss potential outcomes and implications.
Procedure Description
- Blood Sample Collection: A blood sample is taken from the patient.
- DNA Extraction: The DNA is extracted from the blood cells.
- Gene Sequencing: The full sequence of the PMS2 gene is analyzed using advanced sequencing technology to detect any mutations.
- Data Analysis: The results are interpreted by a genetic specialist to identify any pathogenic variants linked to Lynch syndrome.
- Tools and Equipment: Blood collection kits, DNA extraction kits, sequencing machines, and computer software for data interpretation.
- Anesthesia/Sedation: Not applicable as it is a non-invasive procedure.
Duration
The entire procedure, including sample collection and sequencing, can take several weeks, usually around 2-4 weeks.
Setting
The blood collection is typically done in a doctor's office, clinic, or hospital. The gene sequencing and analysis occur in specialized laboratories.
Personnel
- Phlebotomist or nurse for blood collection
- Laboratory technicians for DNA extraction and sequencing
- Geneticists and genetic counselors for results interpretation and patient counseling
Risks and Complications
- Minimal risks associated with blood sample collection such as slight bruising or infection at the puncture site.
- Psychological impacts related to the stress of potential results.
Benefits
- Comprehensive understanding of genetic predisposition to Lynch syndrome
- Early detection and proactive management of colorectal and other associated cancers
- Informative for family planning and preventative strategies for at-risk relatives
Recovery
- Immediate resumption of normal activities post-blood collection
- Follow-up genetic counseling to discuss results and implications
Alternatives
- Targeted Mutation Analysis: Checks for specific known family mutations, which can be faster but less comprehensive.
- Panel Testing: Analysis of multiple genes associated with Lynch syndrome and other hereditary cancers, providing broader genetic information.
- Pros and cons vary based on the individual's family history and the level of detail required.
Patient Experience
- The blood draw is usually quick and only slightly uncomfortable.
- Patients might experience anxiety while awaiting results. Genetic counseling can help manage this.
- No significant pain or discomfort post-procedure.