title: Auditory neuropathy in Brown-Vialetto-Van Laere syndrome due to riboflavin transporter RFVT2 deficiency.
abstract: Mutations in the genes encoding the riboflavin transporters RFVT2 and RFVT3 have been identified in Brown-Vialetto-Van Laere syndrome, a neurodegenerative disorder characterized by hearing loss and pontobulbar palsy. Treatment with riboflavin has been shown to benefit individuals with the phenotype of RFVT2 deficiency. Understanding the characteristics of hearing loss in riboflavin transporter deficiency would enable early diagnosis and therapy.
  
  
  
  We performed hearing assessments in seven children (from four families) with RFVT2 deficiency and reviewed results from previous assessments. Assessments were repeated after 12 months and 24 months of riboflavin therapy and after cochlear implantation in one individual.
  
  
  
  Hearing loss in these individuals was due to auditory neuropathy spectrum disorder (ANSD). Hearing loss was identified between 3 years and 8 years of age and progressed rapidly. Hearing aids were not beneficial. Riboflavin therapy resulted in improvement of hearing thresholds during the first year of treatment in those with recent-onset hearing loss. Cochlear implantation resulted in a significant improvement in speech perception in one individual.
  
  
  
  Riboflavin transporter deficiency should be considered in all children presenting with an auditory neuropathy. Speech perception in children with ANSD due to RFVT2 deficiency may be significantly improved by cochlear implantation.
authors.affiliation: Institute for Neuroscience and Muscle Research and Discipline of Paediatrics and Child Health, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors.forename: Manoj P
authors.initials: MP
authors.lastname: Menezes
authors.affiliation: Department of Audiology, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors.forename: Katherine
authors.initials: K
authors.lastname: O'Brien
authors.affiliation: Sydney Cochlear Implant Centre, Sydney, NSW, Australia.
authors.forename: Mandy
authors.initials: M
authors.lastname: Hill
authors.affiliation: Institute for Neuroscience and Muscle Research and Discipline of Paediatrics and Child Health, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors.forename: Richard
authors.initials: R
authors.lastname: Webster
authors.affiliation: Institute for Neuroscience and Muscle Research and Discipline of Paediatrics and Child Health, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors.forename: Jayne
authors.initials: J
authors.lastname: Antony
authors.affiliation: Institute for Neuroscience and Muscle Research and Discipline of Paediatrics and Child Health, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors.forename: Robert
authors.initials: R
authors.lastname: Ouvrier
authors.affiliation: Department of ENT and Discipline of Paediatrics and Child Health, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors.forename: Catherine
authors.initials: C
authors.lastname: Birman
authors.affiliation: Sydney Cochlear Implant Centre, Sydney, NSW, Australia.
authors.forename: Kirsty
authors.initials: K
authors.lastname: Gardner-Berry
mesh_terms: D000161:Acoustic Stimulation; D017668:Age of Onset; D001299:Audiometry; D010244:Bulbar Palsy, Progressive / Q000150:complications* / Q000209:etiology* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation / Q000379:methods; D004569:Electroencephalography; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D006313:Hearing Loss, Central / Q000150:complications* / Q000188:drug therapy / Q000601:surgery; D006319:Hearing Loss, Sensorineural / Q000150:complications* / Q000209:etiology* / Q000235:genetics; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins / Q000172:deficiency* / Q000235:genetics; D009154:Mutation / Q000235:genetics; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects / Q000235:genetics; D012256:Riboflavin / Q000627:therapeutic use; D012257:Riboflavin Deficiency / Q000150:complications* / Q000188:drug therapy; D013067:Speech Perception / Q000187:drug effects / Q000235:genetics
chemical_list: D026901:Membrane Transport Proteins; C548553:SLC52A3 protein, human; D012256:Riboflavin