Peripheral neuropathy in abetalipoproteinemia

Area of Science:

• Neurology
• Genetics
• Pathology

Background:

• Abetalipoproteinemia is a rare genetic disorder affecting lipid absorption and transport.
• Peripheral neuropathy is a known complication, but its specific pathological features require further elucidation.

Observation:

• Three sisters with abetalipoproteinemia presented with progressive sensory neuropathy.
• Clinical examination revealed diminished sensory action potentials and slowed conduction velocities, primarily in distal nerves.
• Electromyography (EMG) indicated subclinical chronic denervation despite normal motor conduction.

Findings:

• Sural nerve biopsies showed a reduced number of large myelinated fibers (>7 micron).
• Evidence of nerve regeneration, including small fibers and regenerating clusters, was present, particularly in earlier stages.
• Advanced neuropathy stages exhibited paranodal demyelination and regeneration in unmyelinated fibers.

Implications:

• This study highlights the specific pathological changes in peripheral neuropathy associated with abetalipoproteinemia.
• Understanding these features aids in diagnosing and managing this rare genetic condition.
• The findings contribute to the knowledge of nerve degeneration and regeneration mechanisms in metabolic disorders.