Clinical, biochemical, molecular, and histological features of 65 Portuguese patients with mitochondrial disorders.

Introduction: Mitochondrial disorders display remarkable genetic and phenotypic heterogeneity.

Methods: We performed a retrospective analysis of the clinical, histological, biochemical, and genetic features of 65 patients with molecular diagnoses of mitochondrial disorders.

Results: The most common genetic diagnosis was a single large-scale mitochondrial DNA (mtDNA) deletion (41.