Conclusion We suggest performing POLG1 mutation analysis in children with combined oxidative phosphorylation deficiencies in muscle, even if the clinical picture is not Alpers syndrome.
The molecular basis for tissue specificity of the oxidative phosphorylation deficiencies in patients with mutations in the mitochondrial translation factor EFG1.
This is the first report of an association of PTCD3 mutations with Leigh syndrome along with combined oxidative phosphorylation deficiencies caused by defects in the mitochondrial translation machinery.
PNPT1 is a mitochondrial RNA transport protein that has been linked to two discrete phenotypes, namely isolated sensorineural hearing loss (OMIM 614934) and combined oxidative phosphorylation deficiency (OMIM 614932).
In contrast, expression of the ATP5F1D c.245C>T and c.317T>G variants rescued the head-size phenotype but recapitulated the eye and antennae defects seen in other genetic models of mitochondrial oxidative phosphorylation deficiency.
MTO1 (Mitochondrial tRNA Translation Optimization 1), an evolutionarily conserved protein expressed in high-energy demand tissues has been linked to human early-onset combined oxidative phosphorylation deficiency associated with hypertrophic cardiomyopathy, often referred to as combined oxidative phosphorylation deficiency-10 (COXPD10).
The present study extends previous findings by demonstrating that LP-211 treatment (0.25 mg/kg, once per day for 7 days) rescues mitochondrial respiratory chain impairment, oxidative phosphorylation deficiency and the reduced energy status in the brain of heterozygous female mice from two highly validated mouse models of RTT (MeCP2-308 and MeCP2-Bird mice).
AIFM1 mutations have been associated with different clinical phenotypes: a severe infantile encephalopathy with combined oxidative phosphorylation deficiency and the Cowchock syndrome, an X-linked Charcot-Marie-Tooth disease (CMTX4) with axonal sensorimotor neuropathy, deafness and cognitive impairment.
Disease-related mutations in the mitochondrial methionyl-tRNA formyltransferase (MTFMT) gene encoding a critical enzyme for mitochondrial translation have been rarely reported and are described in association with Leigh syndrome and combined oxidative phosphorylation deficiency.
Using a ribozyme designed to degrade the mRNA encoding a critical nuclear-encoded subunit gene of complex I (NDUFA1), we tested whether oxidative phosphorylation deficiency can recapitulate the optic neuropathy of mitochondrial disease.