Whole mitochondrial genome large deletion analysis panel (eg, Kearns-Sayre syndrome, chronic progressive external ophthalmoplegia), including heteroplasmy detection, if performed
CPT4 code
Name of the Procedure:
Whole mitochondrial genome large deletion analysis panel (e.g., Kearns-Sayre syndrome, chronic progressive external ophthalmoplegia), including heteroplasmy detection
Summary
This genetic test analyzes the entire mitochondrial genome to identify large deletions that might be responsible for certain mitochondrial disorders. It can also detect heteroplasmy, which refers to the presence of a mixture of more than one type of mitochondrial DNA within a cell.
Purpose
The test is used to diagnose mitochondrial disorders such as Kearns-Sayre syndrome and chronic progressive external ophthalmoplegia. The goal is to identify large deletions in the mitochondrial DNA, which contribute to these conditions, aiding in the management and treatment planning for affected individuals.
Indications
The test is recommended for patients showing symptoms like muscle weakness, neurological issues, heart block, or ophthalmoplegia (difficulty moving the eyes). It is especially relevant for patients with clinical features indicative of mitochondrial disorders.
Preparation
No special preparation is generally required. Patients might be advised to avoid certain medications before the test to prevent interference with the results. It’s important to discuss any current medications with the healthcare provider.
Procedure Description
- Sample Collection: A blood or tissue sample is collected from the patient.
- DNA Extraction: Mitochondrial DNA is extracted from the collected sample.
- PCR Amplification: The mitochondrial genome is amplified using Polymerase Chain Reaction.
- Sequencing: Next-generation sequencing (NGS) or other technologies are employed to sequence the amplified DNA.
- Data Analysis: Bioinformatics tools analyze the DNA sequences to identify large deletions and detect heteroplasmy.
No anesthesia or sedation is required as it involves a simple sample collection.
Duration
The entire process from sample collection to result interpretation typically takes 2-8 weeks.
Setting
The sample collection is usually done in a hospital or outpatient clinic. The actual DNA analysis happens in a specialized laboratory.
Personnel
- Phlebotomist/Nurse: For sample collection.
- Geneticist/Molecular Biologist: For DNA extraction, sequencing, and data analysis.
- Genetic Counselor: To communicate the results and their implications to the patient.
Risks and Complications
- Sample Collection Risks: Minor bruising or discomfort at the sample collection site.
- Result Interpretation Risks: Misinterpretation of results is possible, highlighting the importance of experienced professionals.
Benefits
- Accurate Diagnosis: Helps in the accurate diagnosis of mitochondrial disorders.
- Tailored Management: Facilitates personalized treatment and management plans.
- Family Planning: Provides valuable information for family planning and genetic counseling.
Recovery
There is no recovery period as the procedure is non-invasive and involves only sample collection. Patients can resume their normal activities immediately.
Alternatives
- Clinical Diagnosis: Based on symptoms and physical examination, but less precise.
- Single Gene Analysis: Can identify mutations in specific genes but might not detect large deletions.
- Muscle Biopsy: More invasive and less comprehensive.
Each alternative has its pros and cons, such as varying degrees of invasiveness and specificity.
Patient Experience
Patients will experience minor discomfort during sample collection, akin to a routine blood draw. Post-procedure, there are no significant physical impacts, and comfort measures such as ice packs can alleviate any mild discomfort from the sample collection site.