Abstract
Background: Arginase 1 Deficiency (ARG1-D) is a rare autosomal recessive urea cycle disorder (UCD) characterized by pathologic elevation of plasma arginine and debilitating manifestations. Based on clinical commonalities and low disease awareness, ARG1-D can be diagnosed as hereditary spastic paraplegia (HSP), leading to treatment delays. Cases: A Hispanic woman with unremarkable medical history experienced progressive lower-limb spasticity in her 20s and received a diagnosis of HSP. She developed significant gait abnormalities and is unable to walk without assistance. More recently, two Hispanic brothers with childhood-onset manifestations including lower-limb spasticity, developmental delays, and seizures presented with suspected HSP. All three patients were ultimately diagnosed with ARG1-D based on plasma arginine several-fold above normal levels and loss-of-function ARG1 variants. Disease progression occurred before ARG1-D was correctly diagnosed. Literature Review: Retrospective analyses demonstrate that diagnostic delays in ARG1-D are common and can be lengthy. Because of clinical similarities between ARG1-D and HSP, such as insidious onset and progressive spasticity, accurate diagnosis of ARG1-D is challenging. Timely ARG1-D diagnosis is critical because this UCD is a treatable genetic cause of progressive lower-limb spasticity. Conclusions: Arginase 1 Deficiency should be considered in HSP differential diagnosis until biochemically/genetically excluded, and should be routinely included in HSP gene panels.
Original language | English (US) |
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Pages (from-to) | 109-114 |
Number of pages | 6 |
Journal | Movement Disorders Clinical Practice |
Volume | 10 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2023 |
Keywords
- differential diagnosis
- hyperargininemia
- inborn error of metabolism
- spasticity
- urea cycle disorder
ASJC Scopus subject areas
- Neurology
- Clinical Neurology