Is the Conductive Hearing Loss in < b > < i > NOG < /i > < /b > -Related Symphalangism Spectrum Disorder Congenital?

We describe a dominant Japanese patient with progressive conductive hearing loss who was diagnosed withNOG-related symphalangism spectrum disorder (NOG-SSD), a spectrum of congenital stapes fixation syndromes caused byNOG mutations. Based on the clinical features, including proximal symphalangism, conductive hearing loss, hyper ­opia, and short, broad middle, and distal phalanges of the thumbs, his family was diagnosed with stapes ankylosis with broad thumbs and toes syndrome (SABTT). Genetic analysis revealed a heterozygous substitution in theNOG gene, c.645C#x3e;A, p.C215* in affected family individuals. He had normal hearing on auditory brainstem response (ABR) testing at ages 9 months and 1 and 2 years. He was followed up to evaluate the hearing level because of his family history of hearing loss caused by SABTT. Follow-up pure tone average testing revealed the development of progressive conductive hearing loss. Stapes surgery was performed, and his post-operative hearing threshold improved to normal in both ears. According to hearing test results, the stapes ankylosis in our SABTT patient seemed to be incomplete at birth and progressive in early childhood. The ABR results in our patient indicated the possibility that newborn hearing screening may not detect conductive hearing loss in patients withNOG-SSD. Hence, children with a family history and/or known congenital joint abnormality should undergo periodic hearing tests due to possible progressive hearing loss. Because...
Source: ORL - Category: ENT & OMF Source Type: research