Phenotypes Associated with This Genotype

Genotype
MGI:5487460

• Allelic Composition: Myo7a^dmbo2/Myo7a^dmbo2
• Genetic Background: involves: C57BL/6J

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

Degeneration and/or misorientation of outer hair cell bundles in Myo7a^ewaso/Myo7a^ewaso and Myo7a^dmbo2/Myo7a^dmbo2 cochlea

hearing/vestibular/ear

hearing/vestibular/ear phenotype ( J:195666 )

N • mice exhibit normal vestibular function, tympanic membrane, bulla, ossicles, supporting cells and zone of polarity reversal of vestibular hair cell bundles

abnormal cochlear hair cell stereociliary bundle morphology ( J:195666 )

• at the apical level

abnormal inner hair cell stereociliary bundle morphology ( J:195666 )

• at 2 weeks at the apical level

decreased inner hair cell stereocilia number ( J:195666 )

• progressive degeneration with additional rows of stereocilia

abnormal orientation of outer hair cell stereociliary bundles ( J:195666 )

• misoriented at P5 in the apical, mid and basal levels

• more so at 2 weeks at all levels

• progressive misorientation with advancing age with disintegration in parts

• however, sensory epithelium degeneration is minimal at 8 weeks and large numbers of outer hair cell bundles are still present

abnormal vestibular hair cell stereociliary bundle morphology ( J:195666 )

• some of the tallest or shortest sterocilia are missing in some bundles

increased or absent threshold for auditory brainstem response ( J:195666 )

• severe from 4 weeks

• however, mice retain some residual hearing at 24 weeks

impaired hearing ( J:195666 )

• severe from 4 weeks

nervous system

abnormal cochlear hair cell stereociliary bundle morphology ( J:195666 )

• at the apical level

abnormal inner hair cell stereociliary bundle morphology ( J:195666 )

• at 2 weeks at the apical level

decreased inner hair cell stereocilia number ( J:195666 )

• progressive degeneration with additional rows of stereocilia

abnormal orientation of outer hair cell stereociliary bundles ( J:195666 )

• misoriented at P5 in the apical, mid and basal levels

• more so at 2 weeks at all levels

• progressive misorientation with advancing age with disintegration in parts

• however, sensory epithelium degeneration is minimal at 8 weeks and large numbers of outer hair cell bundles are still present

abnormal vestibular hair cell stereociliary bundle morphology ( J:195666 )

• some of the tallest or shortest sterocilia are missing in some bundles

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
autosomal recessive nonsyndromic deafness 2		DOID:0110477	OMIM:600060	J:195666