Atypical presentation of PLAN-associated NBIA

PLA2G6-associated neurodegeneration (PLAN) is a complex group of neurodegenerative diseases that result from mutations in a gene known as PLA2G6. According to the age of onset and clinical features, PLAN can be mainly classified into four subtypes: infantile neuroaxonal dystrophy (INAD), atypical neuroaxonal dystrophy (ANAD), adult-onset dystonia-parkinsonism and autosomal recessive early-onset parkinsonism. The onset of INAD and ANAD occurs in childhood and these diseases manifest as progressive psychomotor deterioration, axial dystonia, spasticity, and ataxia, as well as optic atrophy in some children. Other two manifests in adulthood. Cerebellar cortical atrophy and iron deposition in the globus pallidus and substantia nigra can be detected by Magnetic Resonance Imaging (MRI) in most patients in children. While INAD presents in children less than 3 years and has a more severe progression, ANAD presents after 3 years and has a more slower progression. ANAD patients are cognitively normal before neurological symptoms. We here present a case who initially presented at 2 years with developmental delay, hyperactivity and poor school performance and later after 15 years developed parkinsonian features with tremors in hands. His MRI showed atypical features like T1 hyperintensities in the caudate and putamen and absence of cerebellar atrophy mimicking manganese transporter defect. MRI showed bilateral globus pallidi hypointensities suggesting NBIA. Genetic studies showed likely pathogenic mutation in PLA2G6 gene. PLAN should be considered in the differentials of hyperintense basal ganglia on T1 weighed images
Keywords: Neuroaxonal dystrophy, PLA2G6 associated neurodegeneration, Neurodegeneration with brain iron accumulation