Analysis of clinical audiological characteristics in children with Williams syndrome in China

Williams Syndrome (WS) is a neurodevelopmental disorder caused by microdeletion on chromosome 7. Hearing loss (HL) is common in this population but is rarely taken seriously. Previous studies had small sample sizes and mixed conclusions, and few studies have investigated HL in children with WS.

To investigate audiological characteristics of children with WS, analyze the influence factors, and to provide scientific basis for further improvement of ear and hearing care in children with WS.

Children with WS aged 0-18yrs, followed up in the Department of Pediatric Healthcare of the Children's Hospital of Zhejiang University School of Medicine from June 2020 to June 2024 were enrolled in this study. Children aged 0-18yrs who came in the same period for health examination were matched as the control group. Both groups underwent a series of audiological examinations such as tympanogram, distortion product otoacoustic emission (DPOAE), auditory brainstem response (ABR) and pure-tone audiometry (PTA), to analyze the audiological characteristics of WS at different ages, and their difference with control group. Tympanogram and DPOAE were suggested to retest 1 year later and the results of first and second test were also compared.

Tympanogram and DPOAE were completed in 130 WS and control subjects, ranging in age from 1.0 to 12.4 years in the WS group and 0.8-13.1 years in the control group. The passing rate of tympanogram and DPOAE in WS was significantly decreased when compared with control group (p < 0.05), and these differences were found in all age groups. The lower DPOAE passing rate still remain after the tympanogram abnormal data were excluded. The SNR of 2000-5000 Hz were statistically lower in children with WS after tympanogram, DPOAE abnormal data were excluded. Tympanogram and DPOAE were rested in 25 WS 1 year later, and no significant difference was found in the passing rate of these test. ABR tests were completed in 28 WS and 44 control subjects, ranging in age from 0.7 to 5.2 years in the WS group and 0.4-5.2 years in the control group. Threshold of ABR in WS was higher than control group. The latency of wave I, III and the interpeak latency I-III in WS were significantly longer (p < 0.05), and the interpeak latency III-V was significantly shorter than that in control group (p < 0.05). PTA were completed in 20 WS and 28 control subjects, ranging in age from 5.9 to 13.7 years in the WS group and 5.9-12.5 years in the control group. 50% of WS was assessed as HL by PTA, with conductive hearing loss (CHL) in 60%, sensorineural hearing loss (SNHL) in 20% and mixed hearing loss (MHL) in 20%, most were mildly. The threshold of 250-8000 Hz in WS group were significantly higher than that in control group (p < 0.05), either in air or bone conduction.

This study revealed that children with WS frequently exhibit middle and inner ear dysfunction, often accompanied by HL or subclinical cochlear impairment, which can emerge before age 3. Prolonged ABR latency indicates delayed auditory nerve myelination, while shortened interpeak latency III-V may serve as an electrophysiological marker in this population. Long-term, regular hearing follow-up is recommended to enable early HL detection and timely treatment of contributing conditions.