The influence of karyotype on the auricle, otitis media and hearing in Turner syndrome.
The study has investigated the relationship between the chromosomal aberration and ear and/or hearing disorders in 115 girls/women with Turner syndrome (TS). A dose-response relationship was found between the karyotype and hearing function. Hearing deteriorated more rapidly with increasing age in TS women lacking the whole p-arm of chromosome X (i.e. monosomy 45,X, or isochromosome cases 46,X,i(Xq)) as compared to women having a partial deletion of the p-arm (structural deletions or mosaicism cases), who, in turn, had poorer hearing than a female random population sample (46,XX) (P<0.001). Moreover, TS subjects having total deletion of the p-arm were three times more likely to have auricular anomalies or conductive hearing loss due to otitis media than subjects with partial deletion (P<0. 05). The results support the hypothesis that lack of growth-regulating genes such as the short stature homeobox-containing gene (SHOX), which is located within the pseudo-autosomal region on the p-arm of the X chromosome, may increase the occurrence of auricular malformations and otitis media and also induce an earlier loss of hearing function. Accordingly, the ear and hearing disorders in TS may be a result of growth disturbances of the auricle, the mastoid, the Eustachian tube and the organ of Corti during development. It is suggested that karyotype may be used as a predictor for future ear and hearing problems in TS.
Barrenäs
M L
ML
Department of Audiology, Sahlgrenska University Hospital, Göteborg University, S-413 45, Göteborg, Sweden. Marie-Louise.Barrens@medicine.orlss.gu.se
Nylén
O
O
Hanson
C
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D004431:Ear, External / Q000002:abnormalities*; D005260:Female; D006309:Hearing; D006314:Hearing Loss, Conductive / Q000150:complications / Q000235:genetics; D006801:Humans; D007621:Karyotyping; D008875:Middle Aged; D010033:Otitis Media / Q000150:complications / Q000503:physiopathology*; D014424:Turner Syndrome / Q000150:complications / Q000235:genetics* / Q000503:physiopathology