Mitochondrial Complex I Deficiency / Leigh Syndrome (FOXRED1)
Mitochondrial complex I deficiency and Leigh syndrome (FOXRED1-related) are rare, autosomal recessive disorders caused by pathogenic variants in the gene FOXRED1. The onset is typically in infancy. The brain, heart, and skeletal muscles are primarily affected. Neuromuscular problems include exercise intolerance, myalgia, and hypotonia. Neurological deficits include ataxia, encephalopathy, dystonia, epilepsy, and intellectual disability. Hypertrophic cardiomyopathy has been described. Lactic acidosis can occur, causing rapid breathing, nausea, vomiting, and may cause infant death. Life expectancy is reduced. No clear genotype-phenotype correlation has been established.
For information about carrier frequency and residual risk, please see the residual risk table.