LGMD R18 Mimicking Wilson Disease: 6-Year Longitudinal Muscle MRI Evolution and Clinical Insights into TRAPPC11 Mutation.

Background and Clinical Significance: Limb-girdle muscular dystrophy R18 is a rare autosomal recessive disorder that may present with both muscular and hepatic involvement, potentially leading to diagnostic confusion. Longitudinal MRI data documenting this disease from childhood remain scarce. Case Presentation: We report a female patient with disease onset that occurred at 8 years of age, initially presenting with elevated liver enzymes and decreased ceruloplasmin levels, which raised suspicion of Wilson's disease. Genetic testing confirmed TRAPPC11 mutation. Serial MRI scans of the thigh muscles over a six-year period demonstrated progressive fatty infiltration, predominantly affecting the adductor magnus and posterior thigh muscles, with relative sparing of the gracilis and anterior compartment muscles. Conclusions: This case highlights that limb-girdle muscular dystrophy R18 can clinically mimic Wilson disease. Longitudinal muscle MRI offers valuable diagnostic insights and reveals a characteristic pattern of muscle involvement.