3.1 Clinical manifestations and genetic results
The clinical manifestations, genetic results in the four patients are
shown in Table 1. The patients had no mental retardation or growth
delay. All patients failed newborn hearing screening and were diagnosed
with bilateral profound HI soon after birth. They all presented typical
BOR syndrome with at least two major and two minor items according to
the criteria by Chang et al (1). Physical examination
revealed preauricular pits in all cases but branchial anomalies just
existed in Case 2 and 4 , who also had family history of hearing loss.
Bone imaging studies using high-resolution computerized tomography
revealed abnormal inner ear structures in all three patients. Three
cases showed cochlear nerve dysplasia. Additionally, genetic examination
was performed in all cases, case 2 using whole-exome sequencing, case
1,3,4 using Hereditary Hearing Loss panel assay (Mygenostics
Corporation, Beijing, PRC). Pathogenic variants in the EYA1 gene
were identified only in case 4, which had been reported to be causally
linked to BOR syndrome.
Early intervention with hearing aids was provided, and all the patient
benefitted little from intensive aural rehabilitation.