Eya1 heterozygotes show renal abnormalities and a conductive hearing loss similar to BOR syndrome, whereas Eya1 homozygotes lack ears and kidneys due to defective inductive tissue interactions and apoptotic regression of the organ primordia.
Eya1 heterozygotes show renal abnormalities and a conductive hearing loss similar to BOR syndrome, whereas Eya1 homozygotes lack ears and kidneys due to defective inductive tissue interactions and apoptotic regression of the organ primordia.
The temporal bone pathologic correlate for conductive hearing loss in this patient with a NOG mutation was circumferentially calcified cartilage bridging the stapedovestibular joint space.
We propose that the decreased binding affinity of NOG with the p.R136C mutation to HSPG leads to an excess of BMP signaling and underlies the SYM1 and conductive hearing loss phenotype of carriers.
Haploinsufficiency of NOG gene has been implicated in the development of conductive hearing loss, skeletal anomalies including symphalangism, contractures of joints, and hyperopia in our patient and may also contribute to the development of tracheo-esophageal fistula and/or esophageal atresia.
These clinical and molecular findings suggest that (1) a broader range of conductive hearing-loss phenotypes are associated with NOG mutations than had previously been recognized, (2) patients with sporadic or familial nonsyndromic otosclerosis should be evaluated for mild features of this syndrome, and (3) NOG alterations should be considered in conductive hearing loss with subtle clinical and skeletal features, even in the absence of symphalangism.
High-resolution temporal bone CT scans of children (n = 21) with DFNB1 SNHL were compared to age-matched controls with either conductive hearing loss (CHL, n = 33) or a nonsyndromic, non-DFNB1 SNHL (n = 33).
Together, these results identify a role for Fgfr2 in development of the middle ear skeletal tissues and suggest potential causes for conductive hearing loss in LADD syndrome.
Audiological and surgical evidence for the presence of a third window effect for the conductive hearing loss in DFNX2 deafness irrespective of types of mutations.
Lesions in the epithelially expressed human gene FRAS1 cause Fraser syndrome, a complex disease with variable symptoms, including facial deformities and conductive hearing loss.