Genetic Feature of Congenital Hearing Loss in Chinese Population

Whole exome sequencing data

DNA of neonate extracted from blood sample by heel prick or collection of cord blood will be perform whole exome sequencing to present genetic features. By sequencing all protein-coding regions, WES uncovers mutations that can inform diagnostic, therapeutic, and preventive strategies. Key outcome measures from WES include the detection of single nucleotide polymorphisms, insertions, deletions, and structural variants. These outcomes are critical for diagnosing genetic disorders, personalizing treatments, and assessing disease risk. The analysis involves aligning reads to a reference genome, calling variants, and interpreting their clinical significance. WES data thus serves as a cornerstone in genetic research and personalized medicine, enabling a deeper understanding of the genetic underpinnings of diseases and tailoring healthcare approaches to individual genetic profiles.

TEOAE-based otoacoustic emissions test outcome measure

In analyzing Transient Evoked Otoacoustic Emissions (TEOAE), key factors include response reproducibility, which indicates consistent cochlear responses, and signal-to-noise ratio (SNR), where a value above 3 dB suggests clear cochlear emissions against background noise. The Response Spectrum provides a frequency-specific look at cochlear performance, essential for identifying potential hearing issues. A 'Pass' in the TEOAE test denotes normal cochlear function, while a 'Refer' indicates the need for further hearing evaluations.

Auditory brainstem response testing

In auditory brainstem response (ABR) testing, waveform reproducibility and waveform latency, especially of Wave V, are key. High reproducibility indicates reliable signal transmission, suggesting a healthy auditory system. Appropriate latency for Wave V indicates efficient signal processing. Frequency-Specific Responses highlight the brainstem's reaction across different sound frequencies, aiding in identifying potential issues. 'Normal' ABR results reflect functional auditory pathways, while 'Abnormal' ones prompt further investigation.

Acoustic impedance

Acoustic impedance, a critical parameter in sound wave dynamics, quantifies a medium's opposition to sound propagation, expressed as the ratio of acoustic pressure to particle velocity. This parameter is shaped by the medium's density and the speed of sound through it, pivotal for understanding sound behavior in various environments. In audiology, specifically in tympanometry, impedance measurements diagnose middle ear conditions by assessing how sound waves are absorbed or reflected, revealing conditions like effusion or tympanic membrane perforations. The results are typically classified into Jerger types, which categorize middle ear function based on the impedance curve's shape and peak characteristics, providing a detailed insight into middle ear health. High impedance may indicate obstructions or stiffness in the middle ear, while low impedance could suggest perforations or discontinuities.

Audiogram

Pure-tone threshold testing is a cornerstone of audiological assessment, used to determine the softest level at which an individual can hear sounds of specific frequencies. During the test, pure tones of various frequencies are presented through headphones or earphones to one ear at a time, or through a speaker for bone conduction testing. The process begins at an audible level, gradually decreasing until the sound is no longer heard, then slightly increasing until it is heard again. This method helps identify the threshold, or the lowest level at which a sound is perceived 50% of the time for each frequency tested, typically ranging from low (250 Hz) to high (8000 Hz) frequencies.