Childhood POLG-related disorders: Focus on polyradiculoneuropathy

Abstract

Pathogenic variants in POLG are involved in a large spectrum of neurological, gastrointestinal and liver impairments. Children affected with POLG-related disorders rarely exhibit peripheral neuropathy, the latter being most often described in adults as axonal polyneuropathy. Our aim was to focus on electrophysiological findings in young children affected with POLG-related disorder. We report herein 6 unrelated early-onset POLG patients presenting with an atypical and severe polyradiculoneuropathy mimicking Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). All these patients also exhibited severe intestinal dysmotility and liver disease. Different compound heterozygous pathogenic variants in POLG were found and 4/6 patients shared the same heterozygous R232H variation. POLG-related disorders should therefore be considered in the setting of atypical childhood onset CIDP with gastrointestinal and liver impairments.

Keywords: CIDP; POLG; chronic inflammatory demyelinating polyneuropathy; mitochondria; mitochondrial disorders.