The MYO7A gene encodes a motor protein with a key role in the organization of stereocilia in auditory and vestibular hair cells. Rare variants in the MYO7A (myosin VIIA) gene may cause autosomal dominant (AD) or autosomal recessive (AR) sensorineural hearing loss (SNHL) accompanied by vestibular dysfunction or retinitis pigmentosa (Usher syndrome type 1B). Familial Meniere's disease (MD) is a rare inner ear syndrome mainly characterized by low-frequency sensorineural hearing loss and episodic vertigo associated with tinnitus. Familial aggregation has been found in 6-8% of sporadic cases, and most of the reported genes were involved in single families. Thus, this study aimed to search for relevant genes not previously linked to familial MD. Through exome sequencing and segregation analysis in 62 MD families, we have found a total of 1 novel and 8 rare heterozygous variants in the MYO7A gene in 9 non-related families. Carriers of rare variants in MYO7A showed autosomal dominant or autosomal recessive SNHL in familial MD. Additionally, some novel and rare variants in other genes involved in the organization of the stereocilia links such as CDH23, PCDH15 or ADGRV1 co-segregated in the same patients. Our findings reveal a co-segregation of rare variants in the MYO7A gene and other structural myosin VIIA binding proteins involved in the tip and ankle links of the hair cell stereocilia. We suggest that recessive digenic inheritance involving these genes could affect the ultrastructure of the stereocilia links in familial MD.
13 July 2020 in European Archives of Oto-Rhino-Laryngology
Purpose: To establish a standardized reporting system of cholesteatoma, the ChOLE classification has recently been introduced. We here aimed to systematically investigate the association between the ChOLE classification and (i) hearing, (ii) recidivism rate, and (iii) postoperative complications. These data may increase the utility of the ChOLE classification in clinical practice and research by stratifying patients according to expected outcomes or risks for complications. Methods: In this prospective multicentric study, we included adult patients undergoing tympanomastoid surgery due to cholesteatoma. Main outcome measures included the association of the ChOLE classification system with (i) audiometric data including air conduction (AC) and bone conduction (BC) pure-tone average (PTA), and the air–bone gap (ABG), (ii) recidivism and complication. Results: A total of 160 patients suffering from cholesteatoma were included. ChOLE stage distribution was stage I in 23 (14%), stage II in 128 (80%), and stage III in 9 (6%) patients. The ChOLE stage was associated with the postoperative AC PTA (p = 0.05) and the postoperative BC PTA (p = 0.02). Further, the status of the ossicular chain after surgery (ChOLE subdivision “O”) was associated with both the postoperative ABG (p = 0.0001) and the postoperative AC PTA (p = 0.003). Moreover, we found an association between complications (ChOLE subdivision “L) and both the postoperative BC PTA (p = 0.04) and the postoperative ABG (p = 0.04). No association between the ChOLE stage was found to both cholesteatoma recidivism and surgical complications. Conclusion: The ChOLE classification is a new system to classify cholesteatomas. We provide evidence that hearing outcomes vary among different ChOLE stages. In particular, hearing outcomes are associated with the ChOLE subdivision “O” and “L”. Thus, the ChOLE classification system has a predictive value regarding hearing outcomes.
Posttraumatic Meniere's syndrome is a rare clinical entity. The pathomechanism by which temporal bone trauma leads to fluctuating audiovestibular symptoms, in some cases with a delay of onset many years after trauma, remains elusive. Here, a clinical case and the respective temporal bone imaging data were reviewed to investigate the underlying inner ear pathology. A 44-year-old patient presented with left-sided Meniere's syndrome 34 years after he suffered an ipsilateral temporal bone fracture caused by a car accident. Clinical imaging showed left cochleovestibular hydrops (gadolinium-enhanced MRI) and bony obliteration of the left VA (CT imaging), resulting in discontinuity of the ES. Our findings suggest that a temporal bone fracture with a “retrolabyrinthine” course, traversing the VA, caused intraaqueductal callus bone formation and progressive blockage of the VA. As a result, the extraosseous (distal) endolymphatic sac (eES) became separated from the cochleovestibular labyrinth, an event that presumably underlies endolymphatic hydrops formation and that precipitates the onset of clinical Meniere's symptoms in this case.