Late infantile ceroid-lipofuscinoses. An ultrastructural study

Area of Science:

• Neurology
• Pathology
• Genetics

Background:

• Late infantile ceroid-lipofuscinosis (LIC) are rare, fatal neurodegenerative lysosomal storage diseases.
• Skin biopsies offer a potential diagnostic window into cellular pathology in LIC.
• Previous studies have indicated ultrastructural abnormalities in LIC, but further characterization is needed.

Purpose of the Study:

• To investigate and detail the ultrastructural skin patterns in five cases of late infantile ceroid-lipofuscinosis (LIC).
• To identify characteristic cytosomes and lipopigment inclusions in epidermal and dermal cells.
• To assess the diagnostic utility of electron microscopy in LIC.

Main Methods:

• Skin biopsies were obtained from five patients diagnosed with LIC (two classic, three variants).
• Ultrastructural examination using electron microscopy was performed on the skin samples.
• Analysis focused on identifying and characterizing cytosomes, lipofuscin, and other cellular inclusions.

Main Results:

• Characteristic cytosomes, including lipofuscin (osmiophilic granular material, curvilinear bodies, fingerprint bodies), were identified in various epidermal and dermal cells.
• Diverse ultrastructural profiles were observed concurrently within each case, often associated with lipid droplets.
• Variable involvement of myelinated sheaths was noted across the cases, possibly linked to genetic factors or disease stage.

Conclusions:

• Clinically unaffected skin exhibits significant ultrastructural changes in LIC.
• Electron microscopy of skin biopsies is a crucial diagnostic method for LIC, especially when biochemical assays are unavailable.
• Ultrastructural findings supplement clinical and electrophysiological data for diagnosing ceroid-lipofuscinoses.