In simple words: This test examines the genetic material within mitochondria (the energy centers of cells) to look for large missing pieces of DNA. These missing pieces can cause problems with how nerves and muscles work. The test can also check if some of the mitochondrial DNA is mutated and some is normal, which is called heteroplasmy.

This test analyzes the entire mitochondrial genome for large deletions (missing sections of DNA) that are associated with neuromuscular disorders. It also includes heteroplasmy detection, which identifies whether some mitochondrial DNA exhibits mutations while other portions remain normal. This test is distinct from full genome sequencing of mitochondrial DNA (81460) and analysis of nuclear-encoded mitochondrial genes (81440).

Example 1: A physician orders this test for a patient with suspected Kearns-Sayre syndrome, a neuromuscular disorder associated with large mitochondrial DNA deletions., A patient presents with chronic progressive external ophthalmoplegia (CPEO), and this test is used to assess the presence and extent of mitochondrial DNA deletions., A child exhibits symptoms of a mitochondrial disorder, such as muscle weakness and developmental delays, and this test is performed to investigate potential large-scale deletions in mitochondrial DNA.

Documentation should include the reason for testing, relevant clinical findings, and family history if applicable. The patient's informed consent should also be documented.