Electron Microscopy Can Still Have a Role in the Diagnosis of Selected Inborn Errors of Metabolism

Area of Science:

• Pathology
• Metabolic Disorders
• Diagnostic Techniques

Background:

• Anatomic pathology laboratories are increasingly discontinuing electron microscopy (EM) services.
• Inborn errors of metabolism (IEM) are a group of genetic disorders that can have severe consequences if not diagnosed and managed promptly.

Purpose of the Study:

• To retrospectively review autopsies to identify cases of IEM.
• To determine the diagnostic contribution of electron microscopy (EM) in identifying IEM.
• To evaluate EM as a diagnostic tool for IEM in resource-limited settings.

Main Methods:

• Retrospective review of 900 perinatal and pediatric autopsies over 17 years.
• Identification of cases diagnosed with inborn errors of metabolism (IEM).
• Assessment of the role of electron microscopy (EM) in the diagnostic process for these IEM cases.

Main Results:

• Seven cases (1%) of IEM were identified, including Pompe disease, I-cell disease, bile acid synthesis defect, and mitochondrial disease (Leigh syndrome).
• Electron microscopy (EM) was crucial for diagnosing I-cell disease and Pompe disease.
• EM facilitated prenatal diagnosis in two cases with a positive family history.

Conclusions:

• Electron microscopy (EM) remains a valuable diagnostic tool for inborn errors of metabolism (IEM), particularly in settings where advanced genetic testing is inaccessible or costly.
• EM provides an affordable and timely alternative for IEM diagnosis, aiding patient management and screening for genetic testing.
• The study highlights the continued relevance of EM in specific diagnostic contexts within pathology.