A 6-year-old boy was diagnosed with both Duchenne muscular dystrophy (DMD) and Wilson disease (WD), according to a case report recently published in Frontiers in Pediatrics. WD is a rare disorder in which copper levels accumulate abnormally in the body, potentially causing damage to organs such as the brain and the liver.
The young boy was admitted to the authors’ neurology department because of weakness in his legs and difficulty squatting. The authors noted he swayed from side to side when walking and could not walk long distances. In addition, the patient had elevated liver enzymes called transaminases.
Approximately a year earlier, the patient had been diagnosed with WD after laboratory investigations showed abnormally low ceruloplasmin levels. Low ceruloplasmin levels are a strong indicator of WD. The patient was given penicillamine to expedite copper removal.
During his current presentation, the boy’s physicians proceeded to perform an examination of all his systems. A neurological examination was normal except for the patient’s “duck step” gait of walking. While the patient had good muscle strength in his upper limbs (grade 5, which is the maximum score possible), the muscle strength of the upper part of his lower limbs was grade 4, and grade 4+ in the lower part of his lower limbs.
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Further testing followed, covering imaging, nerve studies and more laboratory investigations. Genetic investigations showed two pathogenic (ie, diseased) mutations that were later identified as having originated from the child’s parents. In addition, the boy’s management team discovered a pathogenic mutation site in the DMD gene.
Having performed a thorough clinical assessment of the child, physicians arrived at a diagnosis of WD with DMD. The child was given dimercaptopropanesulfonic acid for two weeks to reduce the copper levels in his body. Prednisone acetate was added to alleviate inflammation, and glutathione for its detoxifying and anti-inflammatory properties.
At a follow-up visit at age 7, there were no signs of lower limb weakness having progressed. The North Star Ambulatory Assessment score (NSAA), which measures motor performance, remained at 22 from the child’s initial assessment, meaning that the patient’s motor performance had stabilized. The NSAA is used to measure motor performance on a scale of 0 to 34, with higher scores indicating better performance.
“The co-occurrence of WD and DMD is exceedingly rare, and children with WD and DMD may present with an atypical phenotype, given the presence of two genetic causative factors,” the authors of the report wrote. “Therefore, clinicians should perform comprehensive and systematic assessments of the patient’s history and physical examinations.”
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