Neuronal ceroid lipofuscinosis type-11 in an adolescent

Abstract

Neuronal ceroid lipofuscinosis (NCL) is a group of progressive neurodegenerative disorders characterized by intracellular accumulation of ceroid lipopigments. Based on gene defect of NCL-associated proteins, 14 types of NCL have been described till date. NCL type 11 was first described in 2014 in two siblings as adult-onset NCL and was found to be due to a homozygous progranulin gene mutation. These siblings had progressive retinopathy, recurrent generalized seizures, moderate ataxia and subtle cognitive dysfunction. Palinopsia was present and MRI showed selective and severe cerebellar atrophy which was progressive with age. There have been no further reports of NCL 11 in literature. We here present a 14-year old girl born to second degree consanguineous couple who presented with gradually increasing frequency of seizures for the past 1 year without any signs of visual abnormalities and dementia. She had an elder sister who had progressive seizures and dementia from 8 years of age and died after few years. Her electroencephalogram showed frequent generalized epileptiform discharges and magnetic resonance imaging (MRI) showed pure cerebellar atrophy mainly affecting the vermis. MRI findings suggested a neurodegenerative disorder like NCL and prompted us to go for whole exome screen which revealed NCL type 11 due to homozygous mutation c.912G>A (p.Trp304Ter) in exon 9 of GRN gene (OMIM#614706). To the best of our knowledge this is the third case of NCL 11 and the first from Asia.

Keywords: CLN11; Cerebellar atrophy; Neuronal ceroid lipofuscinosis; Progranulin.