A de novo and novel mutation in the EYA1 gene in a Chinese child with branchio-oto-renal syndrome

Abstract

Branchio-oto-renal (BOR) syndrome is a rare autosomal dominant disorder characterized by branchial cleft fistulae or cysts, preauricular pits, ear malformations, hearing loss, and renal anomalies. Mutations in the human homologue of the Drosophila eyes absent gene (EYA1) are the most common cause of BOR syndrome. PCR and direct sequencing were used to investigate all of the exons and exon-intron boundaries in the EYA1 gene in a patient with BOR syndrome from China. The patient was a child who displayed clinical features of BOR syndrome. Analysis of mutations in the EYA1 gene revealed a novel single base-pair deletion resulting in a truncated protein (c.1381delA; p.R461fs467X), and an analysis of mutations in the family revealed that this mutation was a de novo mutation. This is the first case of BOR syndrome in mainland China to be diagnosed based on clinical manifestations and mutations in the EYA1 gene. The novel c.1381delA mutation detected here expands the spectrum of known mutations in the EYA1 gene.

Keywords: EYA1 gene; branchio-oto-renal syndrome; novel mutation.

Figure 1.

Clinical manifestations of BOR syndrome. (A), scars from surgery to repair fistulae in the preauricular region (B), scars from surgery to remove a branchial cleft cyst in the neck.

Figure 2.

Analysis of mutations in the EYAI gene (the arrow indicates the mutation). P: patient; M: mother; F: father.