abnormal vestibular hair cell morphology abnormal vestibular hair cell stereociliary bundle morphology MP:0004515 MPheno.ontology abnormal vestibular hair bundles abnormal vestibular hair cell stereocilia abnormal vestibular hair cell stereociliary bundles any structural anomaly or disruption of the typical staircase-like arrangement of the mechanosensitive hair bundles which are composed of thick long microvilli (stereocilia) and are located at the apical end of vestibular hair cells of the utricle and saccule