Jacob's Syndrome and Hearing Loss: A Case Study

Jacob's syndrome, or XYY syndrome, is caused by the presence of an extra Y chromosome in each male human cell. Although this extra Y chromosome makes these people taller than the average, they do not show any other unusual physical characteristics. Until now, very few studies have specifically examined the hearing abnormalities of individuals with this syndrome. A four-year-old boy with Jacob's syndrome was referred for an auditory assessment due to speech delay. The test battery results revealed a conductive hearing loss bilaterally based on existing air-bone gaps in pure-tone audiometry, absence of distortion product otoacoustic emissions, and stapedial reflexes. Furthermore, the auditory brainstem responses confirmed a conductive hearing loss, as the interwave interval between waves one, three, and five was normal. Still, the absolute latency of all waves was delayed. These results were consistent with the CT (Computed Tomography) scan images demonstrating stapes footplate fixation. The audiological and imaging findings were supportive of stapes fixation; however, they were not sufficient to establish a definitive etiological diagnosis. Bilateral stapes fixation was suspected in a young boy with Jacob's syndrome. Behavioral, physiological, and electrophysiological hearing assessments indicated mild bilateral conductive hearing loss, with findings that were consistent with and supported by medical imaging. Although the exact etiology of the stapes fixation could not be determined, both congenital and acquired causes were considered. Incorporating comprehensive audiological and otological evaluations into the routine follow-up of children with Jacob's syndrome may facilitate early identification of hearing impairment, particularly during critical periods of speech and language development.