Diagnostic challenges in metabolic myopathies.

Area of Science:

• Biochemistry
• Genetics
• Neurology

Background:

• Metabolic myopathies are a diverse group of disorders affecting cellular energy metabolism.
• These conditions stem from defects in carbohydrate and fatty acid breakdown, encompassing glycogen storage diseases and fatty acid oxidation disorders.
• Clinical presentations vary widely, from severe infantile multisystemic disorders to adult-onset myopathies characterized by exercise intolerance, myoglobinuria, fixed weakness, or cardiomyopathy.

Purpose of the Study:

• To provide an overview of common metabolic myopathy phenotypes and diagnostic approaches.
• To highlight the importance of clinical manifestations in guiding diagnostic investigations.
• To review recent advancements in diagnostic techniques, including Next Generation Sequencing (NGS).

Main Methods:

• Literature search for recent diagnostic techniques and treatment mechanisms.
• Overview of common phenotypes for Pompe disease and lipid metabolism disorders.
• Emphasis on clinical suspicion as the initial step in diagnosis.

Main Results:

• Clinical features like exercise intolerance and myoglobinuria are key indicators in adults.
• Pompe disease phenotypes and enzyme replacement therapy (ERT) mechanisms are discussed.
• Common lipid metabolism disorders and their potential dietary or supplementary treatments are reviewed.

Conclusions:

• Clinical suspicion is paramount for initiating investigations into metabolic myopathies.
• Biochemical and molecular studies, particularly NGS, are essential for definitive diagnosis.
• Understanding diverse clinical patterns aids in timely diagnosis and management of metabolic myopathies.