Molecular Genetic Causes and Clinical Description of Branchio-Oto-renal Syndrome

Abstract

Branchio-oto-renal (BOR) syndrome is an autosomal dominant disease characterized by a combination of hearing impairment with preauricular pits, cervical fistulas or cysts, and various renal abnormalities. Mutations in the EYA1 gene are responsible for 40% of BOR syndrome cases. This study for the first time demonstrates a detailed clinical description and molecular genetic study of BOR syndrome in the Russian Federation among eight Russian patients from four unrelated families. As a result, two pathogenic variants (c.394C>T (p.Gln132*), c.519delT (p.Gln174Asnfs*66), c.1360G>A (p.Gly454Ser)) in the EYA1 gene were detected for the first time in three patients with branchio-oto-renal (BOR) syndrome. The pathogenic variant c.858delC (p.Ile286Leufs*79) primarily identified in the previous study was analyzed. The results obtained in the present study demonstrate a significant contribution of the genetic pathology caused by mutations in the EYA1 gene to the manifestation of BOR syndrome in Russian patients. The frequency of clinical symptoms of BOR syndrome in Russian patients corresponds to foreign data.