Genome sequencing identifies a rare case of moderate Zellweger spectrum disorder caused by a defect: Case report and literature review.

Defects in are associated with a severe neonatal-lethal form of Zellweger spectrum disorder. We report two moderately affected siblings whose clinical and biochemical phenotypes expand the reported spectrum of -related disease. Genome sequencing of an adolescent male with progressive movement disorder, spasticity and neurodegeneration, and previous non-diagnostic plasma very-long chain fatty acid analysis, revealed a homozygous likely pathogenic missense variant in [c.991G > A; p.(Gly331Arg)]. A younger sibling with significant motor decline since the age of three years was also subsequently found to be homozygous for the familial variant. A comprehensive review of the scientific literature identified three additional families with non-lethal infantile- or childhood-onset -related disease, which together with this clinical report illustrate the potential for highly variable disease severity. Our findings demonstrate the diagnostic utility of genome-wide sequencing for identifying clinically and biochemically heterogeneous inherited metabolic disorders such as the peroxisome biogenesis disorders.