Mitochondrial Respiratory Chain Enzyme Analysis (ETC) - Skeletal Muscle

Casandra

Casandra Test Code BA32640Version 1 (DRAFT)

Performing Lab

Lab Baylor GeneticsLab Test ID 3200CPT Codes 82657, 84311

Mitochondrial Respiratory Chain Enzyme Analysis (ETC) - Skeletal Muscle

Clinical Use

Use

The Mitochondrial Respiratory Chain Enzyme Analysis is designed to assess potential enzymatic deficiencies in mitochondrial respiratory chain complex I-IV deficiency. These deficiencies can lead to variable multi-organ disorders, primarily affecting the nervous system, heart, and skeletal muscles. Symptoms may arise at birth or later, including encephalopathy, epilepsy, intellectual disability, ataxia, and dystonia. Other manifestations include hypotonia, myalgia, exercise intolerance, and life-threatening lactic acidosis. Early detection through enzyme analysis is crucial for managing the disorder and preventing severe complications.

Special Instructions

This enzyme analysis is performed on muscle tissue. The following enzymes are analyzed: Ferricyanide:NADH dehydrogenase I, NADH:cytochrome c reductase I-III, Succinate dehydrogenase II, Succinate:cytochrome c reductase II-III, Cytochrome c oxidase IV, and Citrate synthase. Values are normalized to citrate synthase if necessary. Additionally, a similar test can also be performed on skin fibroblasts (test code 3210).

Limitations

Test results may be influenced by the sample quality, handling, and environmental conditions during transport. This test specifically analyzes enzymes related to mitochondrial respiratory chain deficiencies, which may not capture other underlying issues. Additionally, not all mitochondrial deficiencies can be diagnosed through this enzyme analysis, limiting its overall diagnostic efficacy. False negatives or indeterminate results can occur if the disease does not manifest as anticipated. An understanding of the patient's clinical history and presentation is essential for accurate interpretation of results.

Test Details