Hearing growth defects in turner syndrome

Abstract

Turner syndrome (TS) is one of the most common chromosomal abnormalities, occurring in about 50 per 100,000 female live births characterized by the total or partial loss of one X-chromosome in all or some cells. Frequently observed manifestations of TS include short stature, lymphedema, cardiac abnormalities, gonadal dysgenesis, dysmorphic features, ear and hearing problems, and a variety of other problems. Conductive hearing loss (CHL) in patients (pts) with TS is due to recurrent otitis media with effusion, chronic middle ear infection, and cholesteatoma probably as the result of malfunction of the Eustachian tube associated with lymphedema and anatomic shortening of the skull base. The high prevalence of middle ear infections and CHL in TS are probably due to growth disturbances of the structures from the first and second branchial arches. Sensorineural hearing loss (SNHL) is also reported in TS and the hearing decline seems to consist of two patterns: a mid-frequency dip (0.5-3 kHz region) (MF-HL) and a high-frequency loss (>3 kHz region) (HF-HL). SNHL is associated with genotype and phenotype. It seems that SNHL in these pts can become clinically evident during childhood or adolescence, progressive with time, and is independent of middle ear diseases. The evaluation in follow-up of hearing impairment shows that the high-frequency HL remained stable in time. Instead, SNHL with typical dip had a progressive decline. The rate of hearing loss is high at all frequencies but most prominent in the mid-frequency region and the presence of a mid-frequency dip is an especially strong predictor for a progressive decline of hearing. Hearing loss (HL) could have an important impact on social functioning for pts with TS. Clinicians proposed a regular audiological follow-up in TS, especially during childhood, to prevent important middle ear anatomic sequelae and to identify HL at an early stage.