Stereocilin gene variants associated with episodic vertigo: expansion of the DFNB16 phenotype.
Carina Frykholm, Joakim Klar, Tatjana Tomanovic, Adam Ameur, Niklas Dahl
Author Information
Carina Frykholm: Department of Immunology, Genetics and Pathology, Uppsala University and Uppsala University Hospital, Uppsala, Sweden.
Joakim Klar: Department of Immunology, Genetics and Pathology, Uppsala University and Uppsala University Hospital, Uppsala, Sweden. ORCID
Tatjana Tomanovic: Department of Hearing and Balance Disorders, Karolinska Hospital, Solna, Sweden.
Adam Ameur: Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical Centre, Uppsala University, Uppsala, Sweden.
Niklas Dahl: Department of Immunology, Genetics and Pathology, Uppsala University and Uppsala University Hospital, Uppsala, Sweden. niklas.dahl@igp.uu.se.
Vestibular disorders comprise a heterogeneous group of diseases with transient or permanent loss of vestibular function. Vestibulopathy is in most cases associated with migraine, Ménière disease, hereditary ataxias, or sensorineural hearing loss. We identified two brothers and their first cousin affected by hearing loss and episodic vertigo. The brothers were homozygous STRC nonsense variant [c.4027 C > T, p.(Q1343*)], whereas their first cousin was compound heterozygous for the STRC nonsense variant and a 97 kb deletion spanning the entire STRC gene. Clinical investigations confirmed pathological vestibular responses in addition to a characteristic DFNB16 hearing loss. The STRC gene encodes Stereocilin in the cochlea and in the vestibular organ where it ensheathes the kinocilium of the otolithic membranes. Stereocilin is associated with the gel overlaying the vestibular kinocilia, suggesting a role for the protein in sensing balance and spatial orientation. Our findings support such a function for Stereocilin in the vestibular organ and expand the phenotype associated with DFNB16.
References
Am J Med Genet A. 2012 Feb;158A(2):298-308
[PMID: 22147502]
