Mouse Genome Informatics
hm
    Slc26a4tm1Egr/Slc26a4tm1Egr
either: (involves: 129S6/SvEvTac) or (involves: 129S6/SvEvTac * Black Swiss)
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
behavior/neurological
• failed to exhibit a Preyer's reflex to a loud clap
• impairment on a rotarod test
• gait unsteadiness evident upon beginning to walk
• pronounced head bobbing at 3 weeks of age
• pronounced head tilting at 3 weeks of age
• profound circling behavior at 3 weeks of age

hearing/vestibular/ear
• defects detectable at E15
• bulging due to dilation of scala media observed at P1
• in some cases, IHC degeneration is associated with enlarged stereocilia
• inner hair cell degeneration starting between P7 and P15, with variation among different cochleas as well as areas of the same cochlea
• outer hair cell degeneration starting between P7 and P15, with considerable variation among different cochleas as well as areas of the same cochlea
• dilated scala media at P1
• dilated cochlea observed at E15.5-E16.5
• some mice develop dilated semicircular canals
• dilated saccule observed at E15.5-E16.5
• dilated endolymphatic duct starting at E15
• dilated endolymphatic sac starting at E15
• destruction of the otoconial membrane
• almost complete absence of otoconia
• at P30, occasional presence of giant otoconia, when present
• failed to show characteristic waveforms by auditory-evoked brainstem response analyses
• at P28-P42, homozygotes show no characteristic ABR waveforms at intensities up to 100 dB SPL and with all four test stimuli, indicating complete hearing loss
• ~50% of homozygotes exhibit various signs of vestibular dysfunction, including habitual circling behaviour, head-tilting and head-bobbing and/or an abnormal reaching response
• vestibular dysfunction shows variable expressivity with respect to its presence, features and severity, but not age of onset

nervous system
• in some cases, IHC degeneration is associated with enlarged stereocilia
• inner hair cell degeneration starting between P7 and P15, with variation among different cochleas as well as areas of the same cochlea
• outer hair cell degeneration starting between P7 and P15, with considerable variation among different cochleas as well as areas of the same cochlea

Mouse Models of Human Disease
OMIM IDRef(s)
Deafness, Autosomal Recessive 4, with Enlarged Vestibular Aqueduct; 600791 J:67072
Pendred Syndrome; PDS 274600 J:67072