The researchers studied two genes - JAG1 and NOTCH2 - that are mutated in most patients with AGS. They performed hearing tests on 44 patients to determine if their hearing loss was conductive, sensorineural or mixed. The findings in zebrafish and mice revealed that the conductive hearing loss was the most common type, affecting nearly one-third of all ears.
CT scans of five AGS patients revealed a much more complicated picture: a surprising diversity of structural defects in the middle ear with variable effects on hearing.
Only one of the five patients had a stapes defect, specifically associated with conductive hearing loss.Teng concluded that if patients are aware of possible conductive hearing loss earlier in life, then they can more promptly seek medical aids for an improved quality of life.