Name of the Procedure:

PMP22 (Peripheral Myelin Protein 22) Gene Analysis; Duplication/Deletion Analysis
Common names: PMP22 Gene Test, Charcot-Marie-Tooth Genetic Testing

Summary

In this procedure, a genetic test is performed to analyze the PMP22 gene for duplications or deletions. These irregularities are known to cause conditions like Charcot-Marie-Tooth disease and hereditary neuropathy with liability to pressure palsies.

Purpose

This test aims to diagnose genetic abnormalities that lead to peripheral neuropathy disorders. Identifying these genetic issues helps in confirming a diagnosis, guiding treatment, and informing family planning.

Indications

• Symptoms such as muscle weakness, atrophy, reduced sensation, or deformities in the feet or hands.
• Family history of Charcot-Marie-Tooth disease or hereditary neuropathy.
• Clinical signs that suggest these conditions.

Preparation

• No special preparation, such as fasting, is needed.
• Inform your healthcare provider of any medications you are taking.
• A simple blood sample is often required.

Procedure Description

1. A blood sample is collected from the patient.
2. The sample is sent to a specialized laboratory.
3. In the lab, DNA is extracted from the blood cells.
4. Genetic analysis techniques, such as Multiplex Ligation-dependent Probe Amplification (MLPA), are used to detect duplications or deletions within the PMP22 gene.
5. The results are analyzed and interpreted by a genetic specialist.

Duration

The blood draw takes a few minutes, but lab analysis and results can take several weeks.

Setting

The blood sample can be collected in a doctor's office, clinic, or laboratory.

Personnel

• Phlebotomist or nurse for sample collection.
• Geneticist or laboratory technician for analysis.
• Physician or genetic counselor for interpreting and discussing the results.

Risks and Complications

• Minimal risk from blood draw, such as slight discomfort or bruising.
• Rare risk of infection at the puncture site.

Benefits

• Accurate diagnosis of genetic conditions.
• Informed planning for treatment and management.
• Genetic counseling for patients and their families.
• Insight into disease prognosis.

Recovery

• No recovery needed from a blood draw.
• Follow-up appointments might be needed to discuss test results and next steps.

Alternatives

• Electrophysiological studies for nerve conduction.
• Other forms of genetic testing targeting different genes associated with peripheral neuropathy.
• Clinical evaluation and observation.

Patient Experience

• During: Minor discomfort during the blood draw.
• After: No pain, normal activities can be resumed immediately. Await results and follow up with a healthcare provider.