Easy Stapes Subluxation in 22q11.2 Deletion Syndrome: A Clinical Capsule and Literature Review.

Objectives: This report describes iatrogenic stapes subluxation in a 22q11 deletion syndrome patient and reviews the human and murine literature for evidence that these patients have stapes malformations. We aim to alert otologic surgeons regarding the possibility of stapes footplate abnormalities in 22q11 deletion patients.

Patient: An adult woman with known 22q11 deletion syndrome. Additionally, the literature review focused on other patients with 22q11 deletion syndrome as well as mouse models of this disorder.

Interventions: A combination of diagnostic and therapeutic interventions were conducted consisting of middle ear exploration, removal of ossicular chain adhesions, and ultimately ossicular reconstruction.

Results: The stapes footplate was poorly attached to the oval window in our patient. During removal of ossicular adhesions, the entire stapes subluxed requiring placement of a stapes prosthesis. The postoperative audiogram was similar to the preoperative audiogram. Literature review identified one other case of stapes subluxation in a patient with 22q11 deletion syndrome, and mouse models suggest that the stapes footplate has an abnormal connection to the oval window in those affected by 22q11 deletion syndrome.

Conclusions: Patients with 22q11 deletion syndrome have chronic middle ear pathology, and if middle ear exploration is undertaken, the surgeon should be aware that the stapes may have a weak attachment to the oval window. This could put the stapes at risk of injury and contribute to conductive hearing loss.