Neuropathologic Findings in a Patient With Juvenile-Onset Levodopa-Responsive Parkinsonism Due to <i>ATP13A2</i> Mutation
Hsin Fen Chien, Roberta Diehl Rodriguez, Vincenzo Bonifati, Ricardo Nitríni, Carlos Augusto Pasqualucci, Ellen Gelpí, Egberto Reis Barbosa
Abstract
<h3>Objective</h3> To describe the postmortem neuropathologic findings of a patient with Kufor Rakeb syndrome (KRS) due to <i>ATP13A2</i> mutation. KRS is characterized by juvenile-onset levodopa-responsive parkinsonism associated with pyramidal signs, supranuclear gaze palsy, and cognitive impairment. <h3>Methods</h3> A detailed neuropathologic analysis of the brain was performed. The patient had a genetically confirmed <i>ATP13A2</i> homozygous missense mutation and died at age 38 years, which was 26 years after the onset of his symptoms. <h3>Results</h3> The main brain neuropathologic findings were widespread neuronal and glial lipofuscin accumulation with no Lewy body–type inclusions and absence of <i>α</i>-synuclein–positive, tau-positive, <i>β</i>-amyloid–positive, and TDP-43 protein–positive pathologies. Sparse iron deposits were observed in several brain areas, but no obvious axonal spheroids were identified. <h3>Discussion</h3> This is to our knowledge the first KRS postmortem neuropathologic description. Iron deposits were found but not associated with increased axonal spheroids, as frequently observed in neurodegeneration with brain iron accumulation. <i>ATP13A2</i> mutations have been described in patients with neuronal ceroid lipofuscinosis (CLN). Moreover, animal models with these mutations develop neurodegenerative disorders with CLN pathology. Therefore, our findings support that <i>ATP13A2</i> mutations may be considered a genetic etiology of neuronal lipofuscinosis.