American Board of Psychiatry and Neurology (ABPN) Practice Exam 2025 - Free ABPN Practice Questions and Study Guide

Duchenne's and Becker's muscular dystrophies are indeed linked to a deficiency of dystrophin, a crucial protein in muscle tissue. Dystrophin is part of the dystrophin-glycoprotein complex, which helps to stabilize the muscle cell membrane during contraction and relaxation. In Duchenne muscular dystrophy, the deficiency of dystrophin is caused by mutations in the dystrophin gene, leading to severe muscle degeneration and weakness at an early age. Becker muscular dystrophy, on the other hand, results from a partially functional form of dystrophin due to less severe mutations, which leads to a milder phenotype and a later onset of symptoms.

Understanding the role of dystrophin is essential for grasping the pathophysiology of these conditions. The absence or malfunction of this protein compromises the integrity of muscle fibers, ultimately resulting in muscle wasting and the characteristic symptoms of muscular dystrophy. This crucial connection explains why the deficiency of dystrophin is the underlying factor in both Duchenne's and Becker's muscular dystrophies.