title: COQ6 Mutations in Children With Steroid-Resistant Focal Segmental Glomerulosclerosis and Sensorineural Hearing Loss.
abstract: The phenotypic combination of steroid-resistant focal segmental glomerulosclerosis (SR-FSGS) and sensorineural hearing loss has been mainly reported in patients with mitochondrial cytopathies, including primary coenzyme Q10 (CoQ10) deficiency. In this report of 10 children with SR-FSGS and sensorineural hearing loss, we found 6 patients with biallelic COQ6 mutations. Median age at the onset of nephrotic syndrome was 29 (range, 15-47) months. All patients progressed to end-stage renal disease within a median of 13 (range, 1-27) months after the onset. Kidney biopsy revealed abnormal mitochondrial proliferation in podocytes in all 6 patients. None of the 5 patients who underwent kidney transplantation developed recurrence of FSGS. Primary CoQ10 deficiency due to COQ6 mutations should be considered in children presenting with both SR-FSGS and sensorineural hearing loss. An early diagnosis of COQ6 mutations is essential because the condition is treatable when CoQ10 supplementation is started at the early stage. We recommend early kidney biopsy because detection of abnormal mitochondrial proliferation in podocytes might provide an earlier diagnostic clue.
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Eujin
authors.initials: E
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Yo Han
authors.initials: YH
authors.lastname: Ahn
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea; Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hee Gyung
authors.initials: HG
authors.lastname: Kang
authors.affiliation: Department of Pediatrics, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Kee Hwan
authors.initials: KH
authors.lastname: Yoo
authors.affiliation: Department of Pathology, Korea University College of Medicine, Seoul, Korea.
authors.forename: Nam Hee
authors.initials: NH
authors.lastname: Won
authors.affiliation: Department of Pathology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Kyoung Bun
authors.initials: KB
authors.lastname: Lee
authors.affiliation: Department of Pathology, Seoul National University Hospital, Seoul, Korea; Kidney Research Institute, Medical Research Center, Seoul National University Hospital, Seoul, Korea.
authors.forename: Kyung Chul
authors.initials: KC
authors.lastname: Moon
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Moon-Woo
authors.initials: MW
authors.lastname: Seong
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Tae Rin
authors.initials: TR
authors.lastname: Gwon
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Sung Sup
authors.initials: SS
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea; Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea; Kidney Research Institute, Medical Research Center, Seoul National University Hospital, Seoul, Korea. Electronic address: cheonghi@snu.ac.kr.
authors.forename: Hae Il
authors.initials: HI
authors.lastname: Cheong
mesh_terms: D002675:Child, Preschool; D005260:Female; D005923:Glomerulosclerosis, Focal Segmental / Q000150:complications / Q000235:genetics* / Q000473:pathology; D006319:Hearing Loss, Sensorineural / Q000150:complications / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D014451:Ubiquinone / Q000235:genetics*
chemical_list: C032165:ubiquinone 6; D014451:Ubiquinone
keywords: COQ6 mutation; Steroid-resistant focal segmental glomerulosclerosis (SR-FSGS); case report; children; coenzyme Q10 deficiency; end-stage renal disease (ESRD); kidney biopsy; mitochondrial cytopathy; mitochondrial proliferation in podocytes; pediatric; sensorineural hearing loss