Successful cochlear implantation in a patient with mitochondrial hearing loss and m.625G>A transition

Abstract

Objective: We present a patient with mitochondrial hearing loss and a novel mitochondrial DNA transition, who underwent successful cochlear implantation.Case report: An 11-year-old girl showed epilepsy and progressive hearing loss. Despite the use of hearing aids, she gradually lost her remaining hearing ability. Laboratory data revealed elevated lactate levels, indicating mitochondrial dysfunction. Magnetic resonance imaging showed diffuse, mild brain atrophy. Cochlear implantation was performed, and the patient's hearing ability was markedly improved. Whole mitochondrial DNA genome analysis revealed a novel heteroplasmic mitochondrial 625G>A transition in the transfer RNA gene for phenylalanine. This transition was not detected in blood DNA from the patient's mother and healthy controls. Mitochondrial respiratory chain activities in muscle were predominantly decreased in complex III.Conclusion: This case indicates that cochlear implantation can be a valuable therapeutic option for patients with mitochondrial syndromic hearing loss.

Packaging of the Coenzyme Q₁₀ into a Liposome for Mitochondrial Delivery and the Intracellular Observation in Patient Derived Mitochondrial Disease Cells

“…The phenotype includes epilepsy, hearing loss and elevated lactate levels. 22) Dulbecco's modified Eagle's medium (DMEM) with high glucose and fetal bovine serum (FBS) were purchased from the Invitrogen Corporation (Carlsbad, California). The cells were maintained in DMEM with high glucose and 10% FBS, supplemented with penicillin and streptomycin.…”

“…G625A fibroblasts carry a heteroplasmic mutation in the tRNA for phenylalanine in the mitochondrial DNA, leading to a decreased complex III activity. 22) Liposomes containing an initial amount of 0 and 15 mol% CoQ 10 were prepared by the REV method. We used the REV method to package CoQ 10 in the MITO-Porter, because carriers prepared by this method showed a high recovery rate of CoQ 10 and NBD-DOPE, as shown in Figs.…”

Novel human mitochondrial tRNAphemutation in a patient with hearing impairment: A case study

“…The proportion of heteroplasmy was approximately calculated by using a mixture template standard curve of mutant and wild type (Sudo et al 2011). For detection of structural effect of m.628C .…”

Mitochondrial transgene expression via an artificial mitochondrial DNA vector in cells from a patient with a mitochondrial disease

“…In this study, we used G625A fibroblasts obtained from a patient with a mitochondrial disease. The patient was suffering from MELASlike symptoms including epilepsy, hearing loss and elevated lactate levels [9]. The MITO-Porter is internalized by cells, and the carrier escapes from the endosome into the cytosol.…”

“…The G625A fibroblasts carry a heteroplasmic mutation in the tRNA for phenylalanine in the mitochondrial DNA, leading to a decreased level of mitochondrial complex III activity and membrane potential. The phenotype includes epilepsy, hearing loss and elevated lactate levels[9]. The cells were maintained in DMEM and 10% FBS, supplemented with penicillin and streptomycin.…”