LAUSR

Phospholipase A2 Group VI (PLA2G6)-related neurodegeneration (PLAN) is a form of neurodegeneration with brain iron accumulation (NBIA), which displays genetic and phenotypic heterogeneity. It can present in the following 4 different forms depending on the age of onset and varied clinical features: infantile neuroaxonal dystrophy (INAD), atypical neuroaxonal dystrophy (ANAD), adult-onset dystonia-parkinsonism, and autosomal recessive early-onset parkinsonism. Neuroophthalmological involvement is well known in pantothenate kinase-associated neurodegeneration, the most common form of NBIA, and includes retinal degeneration (pigmentary retinopathy), optic neuropathy, and oculomotor abnormalities. Visual dysfunction also occur in PLAN in the form of optic atrophy predominantly in the INAD and ANAD subtypes. We report an unusual presentation of retinal vasculitis in a patient of adultonset PLAN. A 27-year-old male product of third-degree consanguinity presented with difficulty in walking for 9 months in the form of dragging of feet and right eye visual loss for the past 1 month. There was associated extensor posturing of the trunk with a tendency to fall backward and progressive slowness in activities of daily living. Nonmotor symptoms included apathy, history of urinary frequency and urgency, rapid eye movement sleep behavioral disorder, and constipation. The patient noted acute-onset, painless progressive visual loss in his right eye of 1 month duration. The patient had a similar history of painless progressive visual loss (no perception of light) in the left eye. He was diagnosed with a retinal detachment in 2014 attributed to posterior uveitis and underwent pars plana vitrectomy elsewhere. The patient had a poor postsurgical outcome with loss of vision and phthisis bulbi. On examination at our center, he was unable to perceive light in the left eye, and the acuity was 6/36 in the right eye. Fundus examination revealed pale disc edema with multiple superficial non-necrotizing retinitis patches. Fluorescein angiography revealed attenuated vessels with capillaritis and leakage of dye suggestive of active retinal vasculitis (Fig. 1). There was significant dye leakage from the vessels in the late phase. There were capillary nonperfusion areas in the periphery suggestive of occlusive retinal vasculitis. Examination of extraocular eye movements revealed the presence of square wave jerks with broken pursuits and normal saccades. Tone was spastic with 3+ deep tendon reflexes in the lower limbs and bilateral extensor plantar reflex. Extrapyramidal system examination revealed mask-like facies, decreased blink rate, and slow hypophonic speech. Bradykinesia was present with reduced arm swing bilaterally. There was dystonia predominantly affecting the trunk, hands, and feet (Video S1). Patient was investigated to look for the etiology of retinal vasculitis. Cerebrospinal fluid (CSF) analysis was noncontributory, including negative results for CSF gram stain, acid-fast bacilli (AFB), and venereal disease research laboratory test (VDRL). Viral markers, including human immunodeficiency virus (HIV), were negative. Serum VDRL and Treponema pallidum hemagglutination assay was negative. Work up for autoimmune causes including erythrocyte sedimentation rate (ESR), antinuclear antibody (ANA) quantitative profile (ANA, anti Jo-1, Anti Ro/LA, anti-Smith, Anti Scl70, anti-centromere, and anti U1RNP), and human leukocyte antigen B51 (HLA B51) to rule out Behcet’s disease was normal. Serum protein electrophoresis did not show M band. Nerve conduction studies were normal. Brain magnetic resonance imaging revealed diffuse cerebral atrophy with iron deposition in the bilateral globus pallidus in susceptibility weighted imaging sequences with left optic nerve atrophy (Fig. 2). Genetic tests consisting of screening for spinocerebellar ataxia (SCA) (1, 2, 3, 5, 6, 7, 8, 11, 14, 17, 23), fragile X tremor ataxia syndrome (FXTAS), dentatorubral-pallidoluysian atrophy (DRPLA), and mitochondrial disorders were normal. Clinical exome sequencing revealed a homozygous missense mutation (NM_003560.2: C.2222 G>A; p. Arg 741 Gln) on chromosome 22 suggestive of