POLG Comprehensive - Sequence & Deletion/Duplication Analysis

Casandra

Casandra Test Code BA83626Version 1 (DRAFT)

Performing Lab

Lab Baylor GeneticsLab Test ID 3069CPT Codes 81406, 81479

POLG Comprehensive - Sequence & Deletion/Duplication Analysis

Clinical Use

Use

The POLG Comprehensive Test is designed to identify pathogenic variants associated with a range of inherited POLG-related disorders, which are genetic conditions affecting multiple tissues and organ systems, particularly the nervous system, liver, and muscles. These disorders, resulting from deficiencies in DNA polymerase gamma, present various symptoms such as seizures, mental impairment, drooping eyelids, and liver disease, often diagnosed in children or adults. Individuals with these conditions experience a spectrum of symptoms that are not directly predictable based on identified variants. This test is essential for patients showing clinical symptoms or with a family history of POLG-related disorders, aiding in the understanding of the genetic etiology and guiding management.

Special Instructions

This test is recommended for patients with clinical or suspected POLG disorders, as well as those with symptomatic family histories. Carrier screening is also suggested for couples planning pregnancy. For variants previously identified in affected family members, other specific test codes should be ordered. Detailed instructions for sample collection and specific conditions must be adhered to facilitate accurate results.

Limitations

This analysis may not detect all genetic variants associated with POLG-related disorders. Variants not identified in previous studies or those located in non-coding regions may remain undetected. Similarly, variations in disease penetration mean that not all individuals with a pathogenic variant will exhibit symptoms. The broad spectrum of symptoms and overlap with other conditions complicate diagnosis, necessitating thorough clinical evaluation alongside genetic testing. Not all direct relatives may be tested; however, genetic counseling is recommended if a pathogenic variant is identified in the patient.

Test Details