Novel myophosphorylase mutation (p.Arg94Pro) with progressive exercise intolerance

This is the authors' abstract. We don't add key points for this paper.

Key Clinical Message We present a 16‐year‐old girl with a unique clinical phenotype characterized by rapidly progressive exercise intolerance, transient exertional weakness, and progressive muscle cramps involving all limbs and bulbar muscles, following a first myoglobinuric episode at age 15 years, arising from homozygosity for a novel missense mutation (c.281G>C) in PYGM.