N-Glycanase 1 Deficiency Is a Rare Cause of Pediatric Neurodegeneration With Neuronal Inclusions and Liver Steatosis

Abstract

Pediatric neurodegeneration is extremely rare and devastating to the families involved. We describe a rare case of pediatric neurodegeneration in a child with N-glycanase 1 (NGLY1) deficiency. This child had an autosomal recessive mutation in NGLY1, the gene coding for the enzyme NGLY1 that was found with exome sequencing. NGLY1 catalyzes protein deglycosylation by cleaving the -aspartyl glycosylamine bond of N-linked glycoproteins and is thereby a component of the endoplasmic reticulum-associated degradation pathway. This child passed away at five years of age after a prolonged clinical course with myoclonic epilepsy, choreoathetosis-like movements, lacrimal duct problems, and severe developmental delay. This autopsy case report shows images of the neuronal inclusions and liver steatosis found in this patient with NGLY1 deficiency and offers a detailed clinical history.

Keywords: developmental delay; liver steatosis; myoclonic epilepsy; n-glycanase 1 deficiency; neuronal inclusion; pediatric neurodegeneration.