Sudden bilateral sensorineural deafness in a 5 years old girl with blue sclerae, keratoconus, hypermobility of the joints and hyperelasticity of the skin with a mutation in the ZNF469 gene encoding for Brittle-Cornea-Syndrome

Aims: The Brittle-Cornea-Syndrome is a rare autosomal recessive hereditary generalised connective tissue disease with typical symptoms like high corneal fragility, keratoconus, blue sclerae, hypermobility of the joints and hyperelasticity of the skin. Progressive hearing disorders up to deafness were mentioned as well. Hitherto two mutations are identified concerning the ZNF469 gene and the PRDM5 gene.

Methods: A 5 years old girl was presented with a sudden complete sensorineural bilateral hearing loss. Through a BERA-investigation right-sided no responses were found up to 103 dB, sinistral only a V-wave on 90 dB was found and through an electrocochleography even no responses were found bilaterally. Bilateral arched demineralisations around the cochlea were found in the petrosal thin-layer CT. The cerebral MR-imaging was normal. No improvement was achieved under a therapy with steroids for 10 days. After occurrence of a headache, subfebrile temperatures and vomiting a lumbal puncture was completed. The liquor-analysis was normal with normal Reiber-Diagram and no hints of a lyme-disease or a viral infection were found.

Results: Based on the blue sclerae, the keratoconus, the hypermobility of the joints and the hyperelasticity of the skin we suggested a Brittle-Cornea-Syndrome. This suspected diagnosis could be confirmed genetically. A so far not found new homozygous frameshift mutation in exon2 in the ZNF469 gene could be identified in our patient. Meanwhile a bilateral cochlear implant operation was done.

Summary: The confirmation of our suspected diagnosis of a Brittle-Cornea-Syndrome with typical blue sclerae, a keratoconus, hypermobility of the joints and hyperelasticity of the skin succeded with the help of a genetic analysis. Progressive hearing disorders up to deafness were mentioned before as well, though a sudden complete bilateral sensorineural deafness has not been described before. Infectious, space-consuming lesions or other causes of the sudden bilateral sensorineural deafness could be excluded, in order that a relation to the identified genetic disease could be seen.