Recurrent MECR R258W causes adult-onset optic atrophy: A case report

MECR-related neurologic disorder, also known as mitochondrial enoyl CoA reductase protein-associated neurodegeneration (MEPAN) or dystonia with optic atrophy and basal ganglia abnormalities in childhood (MIM: #617282), is an autosomal recessive inherited disease characterized by a progressive childhood-onset movement disorder and optic atrophy. Here we report a 19-year-old male, presented with progressive visual failure, nystagmus, and right orbital pain, with no history of movement or eye disorder in his childhood. His visual decline started at age 18 years, whereas nystagmus emerged seven months later. Analysis of whole-exome sequencing (WES) revealed a homozygous recurrent variant (NM_016011.5:c.772C > T, p.Arg258Trp) in MECR. These findings suggest phenotypic heterogeneity in MECR-related neurologic disorder, thus, more relevant case screening, will help to delineate the genotype-phenotype correlation of the MECR gene.