I-Cell Disease for USMLE

Overview

• I-Cell Disease is also known as Inclusion Cell Disease.
• It is an inherited lysosomal storage disorder.

Pathophysiology

• Defect: Golgi apparatus fails to phosphorylate mannose residues.
• Consequence:
  • Lack of mannose-6-phosphate (M6P).
  • Lysosomal enzymes are secreted extracellularly rather than delivered to lysosomes.
• Impact:
  • High levels of lysosomal enzymes in bloodstream, causing potential tissue damage.
  • Impaired lysosomal function due to missing enzymes, leading to intracellular build-up of substances.

Clinical Manifestations

• Claw hand deformity.
• Joint stiffness.
• Kyphoscoliosis.
• Clouded cornea.
• Coarse facies.
• Gingival hyperplasia.

Additional Resources

• Visual mnemonics for I-Cell Disease and other Lysosomal Storage Diseases are available on Pixorize for USMLE Step 1 and NBME Shelf Exams.
  • Find more mnemonics here.