Comprehensive Peripheral Neuropathy Review: Genetic, Acquired, Infectious, Metabolic, and Toxic Etiologies with Clinical Features, Pathophysiology, and High-Yield Exam Correlations Verified Questions Complete with A+ Graded Rationales LATEST UPDATED 2026

Comprehensive Peripheral Neuropathy Review: Genetic, Acquired, Infectious, Metabolic, and Toxic Etiologies with Clinical Features, Pathophysiology, and High-Yield Exam Correlations Verified Questions Complete with A+ Graded Rationales LATEST UPDATED 2026 What is peripheral neuropathy? Issue with peripheral nerves that results in weakness, numbness, and tingling - typically DISTAL weakness (sensory loss, pain, autonomic dysfunction) Terminology Review: Principle: Distal weakness is often more common that proximal weakness Charcot-Marie-Tooth disease Type 1 (HY) Inherited Peripheral Neuropathy What gene is duplicated What are the presentations Q stem: young kid that repetitively sprains ankle due to legs giving out Peripheral nerve demyelination gene: duplications of PMP22 Presentation: - first/second decade of life ("school aged child") - frequently sprained ankles, high arches (pes cavus), areflexia - distal calf atrophy = "stork leg deformity" PMP 22 duplications = Charcot-Marie-Tooth disease Type 1 A 7 year old PT presents with their mother to the clinic. She is worried about her child because he keeps spraining his ankles, and has developed high arches. Upon PE you observe areflexia, and distal calf atrophy. What disorder? What gene? Charcot-Marie-Tooth disease Type 1 - gene: PMP22 duplications Charcot-Marie-Tooth Type 2A gene = Inherited Peripheral Neuropathy What gene is mutated What are the presentations mitofusion 2 (MFN2) mutation Presentation: (same as type 1) - first/second decade of life ("school aged child") - frequently sprained ankles, high arches (pes cavus), areflexia - distal calf atrophy = "stork leg deformity" Charcot-Marie-Tooth Type 2B gene = What gene/protein is duplicated What are the presentations Mutations in small GTPase late endosomal protein RAB7 Presentation: (same as type 1) - first/second decade of life ("school aged child") - frequently sprained ankles, high arches (pes cavus), areflexia - distal calf atrophy = "stork leg deformity" Charcot-Marie-Tooth Type 2C = What are the presentations paresis of diaphragm & vocal cords Presentation: (same as type 1) - first/second decade of life ("school aged child") - frequently sprained ankles, high arches (pes cavus), areflexia - distal calf atrophy = "stork leg deformity" Charcot-Marie-Tooth Type 2D gene = What gene is mutated What are the presentations