Click-Evoked Otoacoustic Emissions in Children and Adolescents with Gender Identity Disorder
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Click-evoked otoacoustic emissions (CEOAEs) are echo-like sounds that are produced by the inner ear in response to click-stimuli. CEOAEs generally have a higher amplitude in women compared to men and neonates already show a similar sex difference in CEOAEs. Weaker responses in males are proposed to originate from elevated levels of testosterone during perinatal sexual differentiation. Therefore, CEOAEs may be used as a retrospective indicator of someone’s perinatal androgen environment. Individuals diagnosed with Gender Identity Disorder (GID), according to DSM-IV-TR, are characterized by a strong identification with the other gender and discomfort about their natal sex. Although the etiology of GID is far from established, it is hypothesized that atypical levels of sex steroids during a critical period of sexual differentiation of the brain might play a role. In the present study, we compared CEOAEs in treatment-naïve children and adolescents with early-onset GID (24 natal boys, 23 natal girls) and control subjects (65 boys, 62 girls). We replicated the sex difference in CEOAE response amplitude in the control group. This sex difference, however, was not present in the GID groups. Boys with GID showed stronger, more female-typical CEOAEs whereas girls with GID did not differ in emission strength compared to control girls. Based on the assumption that CEOAE amplitude can be seen as an index of relative androgen exposure, our results provide some evidence for the idea that boys with GID may have been exposed to lower amounts of androgen during early development in comparison to control boys.
KeywordsOtoacoustic emissions Gender Identity Disorder Gender Dysphoria Sex differences Androgen Sexual differentiation
We thank Mrs. Iris Franken-Boot, who kindly assisted with the data collection and helped with the patient recruitment. We further thank Dr. Ir. Emile de Kleine and Prof. Pim van Dijk from the University Medical Center Groningen, who kindly introduced us to the OAE equipment and provided us with example protocols for data collection. This study was funded by a VICI Grant (453-08-003) from the Dutch Science Foundation (Nederlandse Organisatie voor Wetenschappelijk Onderzoek) to J. Bakker. J. Bakker is a Senior Research Associate of the Belgian Fonds National de la Recherche Scientifique.
- American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th ed., text rev.). Washington, DC: Author.Google Scholar
- American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: Author.Google Scholar
- Cohen, J. (1977). Statistical power analysis for behavioral sciences (rev ed.). New York: Academic Press.Google Scholar
- Cohen-Bendahan, C. C. C., Buitelaar, J. K., van Goozen, S. H. M., Orlebeke, J. F., & Cohen-Kettenis, P. T. (2005). Is there an effect of prenatal testosterone on aggression and other behavioral traits? A study comparing same-sex and opposite-sex twin girls. Hormones and Behavior, 47, 230–237.CrossRefPubMedGoogle Scholar
- Driscoll, C., Kei, J., Murdoch, B., McPherson, B., Smyth, V., Latham, S., & Loscher, J. (1999). Transient evoked otoacoustic emissions in two-month-old infants: A normative study. Audiology, 38, 181–186.Google Scholar
- Green, R. (1987). The “sissy boy syndrome” and the development of homosexuality. New Haven, CT: Yale University Press.Google Scholar
- Hall, J. W. (2000). Handbook of otoacoustic emissions. San Diego, CA: Singular Thomson Learning.Google Scholar
- Hare, L., Bernard, P., Sánchez, F. J., Baird, P. N., Vilain, E., Kennedy, T., & Harley, V. R. (2009). Androgen receptor repeat length polymorphism associated with male-to-female transsexualism. Biological Psychiatry, 65, 93–96.Google Scholar
- Heylens, G., De Cuypere, G., Zucker, K. J., Schelfaut, C., Elaut, E., Vanden Bossche, H., et al. (2012). Gender identity disorder in twins: A review of the case report literature. Journal of Sexual Medicine, 9, 751–757.Google Scholar
- Maico Diagnostics. (2009). Pediatricians guide to otoacoustic emissions (OAEs) and tympanometry. Retrieved from http://www.maico-diagnostics.com.
- McFadden, D., & Loehlin, J. C. (1995). On the heritability of spontaneous otoacoustic emissions: A twins study. Hearing Research, 85(1–2), 181–198.Google Scholar
- Morlet, T., Perrin, E., Durrant, J. D., Lapillonne, A., Ferber, C., Duclaux, R., Putet, G., et al. (1996). Development of cochlear active mechanisms in humans differs between gender. Neuroscience Letters, 220, 49–52.Google Scholar
- Pujol, R., & Lavigne-Rebillard, M. (1995). Sensory and neural structures in the developing human cochlea. International Journal of Pediatric Otorhinolaryngology, 32(Suppl.) S177–S182.Google Scholar
- Rodenburg, M., & Hanssens, K. (1998). Audiometrie-Methoden en Klinische Toepassingen. Audiometrie (4th ed.). Bussum: Cautinho.Google Scholar
- Rohde Parfet, K. A., Lamberson, W. R., Rieke, A. R., Cantley, T. C., Ganjam, V. K., vom Saal, F. S., & Day, B. N. (1990). Intrauterine position effects in male and female swine: Subsequent survivability, growth rate, morphology and semen characteristics. Journal of Animal Science, 68, 179–185.Google Scholar
- Saitoh, Y., Sakoda, T., Hazama, M., Funakoshi, H., Ikeda, H., Shibano, A., Yajin, S., et al. (2006). Transient evoked otoacoustic emissions in newborn infants: Effects of ear asymmetry, gender, and age. Journal of Otolaryngology, 35, 133–138.Google Scholar
- Singh, D. (2012). A follow-up study of boys with gender identity disorder. Unpublished doctoral dissertation, University of Toronto.Google Scholar
- Sininger, Y. S., & Cone-Wesson, B. (2004). Asymmetric cochlear processing mimics hemispheric specialization. Science, 305(5690), 1581. doi: 10.1126/science.1100646.
- Vuoksimaa, E., Kaprio, J., Kremen, W. S., Hokkanen, L., Viken, R. J., Tuulio-Henriksson, A., & Rose, R. J. (2010). Having a male co-twin masculinizes mental rotation performance in females. Psychological Science, 21, 1069–1071.Google Scholar
- Williams, T. J., Pepitone, M. E., Christensen, S. E., Cooke, B. M., Huberman, A. D., Breedlove, N. J., Breedlove, T. J., et al. (2000). Finger-length ratios and sexual orientation. Nature, 404, 455–456.Google Scholar