Abstract
PurposeWhen referring to enlarged vestibular aqueduct (EVA) we should differentiate between nonsyndromic enlarged vestibular aqueduct (NSEVA) and Pendred Syndrome (PDS), a disease continuum associated with pathogenic sequence variants of Pendrin’s Gene (SLC26A4) in about half of the cases. The study was aimed to analyse the clinical and audiological features of a monocentric cohort of Caucasian patients with NSEVA/PDS, their genetic assessment and morphological inner ear features.MethodsWe retrospectively reviewed the audiologic, genetic and anamnestic data of 66 patients with NSEVA/PDS followed by our audiology service.ResultsSLC26A4 mutations was significantly correlated with the presence of PDS rather than NSEVA (p < 0.019), with the expression of inner ear malformations (p < 0.001) and with different severity of hearing loss (p = 0.001). Furthermore, patients with PDS showed significantly worse pure tone audiometry (PTA) than patients with NSEVA (p = 0.001). Anatomically normal ears presented significantly better PTA than ears associated with Mondini Malformation or isolated EVA (p < 0.001), but no statistically significative differences have been observed in PTA between patients with Mondini Malformation and isolated EVA.ConclusionNSEVA/PDS must be investigated in all the congenital hearing loss, but also in progressive, late onset, stepwise forms. Even mixed or fluctuating hearing loss may constitute a sign of a NSEVA/PDS pathology. Our findings can confirm the important role of SLC26A4 mutations in determining the phenotype of isolated EVA/PDS, both for the type/degree of the malformation, the hearing impairment and the association with thyroid dysfunction.
Highlights
20% of congenital hearing loss (SNHL) is associated with inner ear malformations (IEM) [1, 2]
An isolated enlarged vestibular aqueduct (EVA) was reported in 47 patients (71%), unilaterally in 9 cases (14%, 5 left, 4 right); bilaterally in 38 cases (57%); a Mondini Malformation was found in 19 patients (29%), unilaterally in 1 case (1,5%), bilaterally in 18 cases (27%)
nonsyndromic enlarged vestibular aqueduct (NSEVA)/Pendred Syndrome (PDS) is a disease continuum presenting a wide spectrum of hearing impairment, vestibular dysfunction, IEM, and thyroid pathologies
Summary
20% of congenital hearing loss (SNHL) is associated with inner ear malformations (IEM) [1, 2]. The enlarged vestibular aqueduct (EVA) is reported to be the most common IEM associated with hearing loss in children, often bilaterally [3,4,5]. When referring to EVA, we should differentiate between nonsyndromic enlarged vestibular aqueduct (NSEVA or DFNB4) and Pendred Syndrome (PDS). Both conditions comprise a wide spectrum of hearing loss, vestibular disfunctions and temporal bone abnormalities, but thyroid pathologies are present in PDS (Fig. 1). For these reasons, NSEVA and PDS should be considered part of a disease continuum [9, 10]. An EVA can be associated with other syndromic conditions, such as distal renal tubular acidosis (dRTA), branchio-oto-renal syndrome (BOR) or Waandenburg syndrome [3, 11, 12]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call