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Extreme skewing of X chromosome inactivation in mothers of homosexual men

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Abstract

Human sexual preference is a sexually dimorphic trait with a substantial genetic component. Linkage of male sexual orientation to markers on the X chromosome has been reported in some families. Here, we measured X chromosome inactivation ratios in 97 mothers of homosexual men and 103 age-matched control women without gay sons. The number of women with extreme skewing of X-inactivation was significantly higher in mothers of gay men (13/97=13%) compared to controls (4/103=4%) and increased in mothers with two or more gay sons (10/44=23%). Our findings support a role for the X chromosome in regulating sexual orientation in a subgroup of gay men.

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Acknowledgements

We would like to thank all the families whose participation in this study made our work possible.

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Authors and Affiliations

  1. Department of Human Genetics, University of California, Los Angeles, CA, USA

    Sven Bocklandt, Steve Horvath & Eric Vilain

  2. Department of Biostatistics, University of California, Los Angeles, CA, USA

    Steve Horvath

  3. Laboratory of Biochemistry, National Cancer Institute, Bethesda, MD, USA

    Sven Bocklandt & Dean H. Hamer

  4. Gonda 5524, 695 Charles Young Drive South, Los Angeles, CA, 90095-7088, USA

    Sven Bocklandt

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  1. Sven Bocklandt
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  2. Steve Horvath
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  3. Eric Vilain
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  4. Dean H. Hamer
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Correspondence to Sven Bocklandt.

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Bocklandt, S., Horvath, S., Vilain, E. et al. Extreme skewing of X chromosome inactivation in mothers of homosexual men. Hum Genet 118, 691–694 (2006). https://doi.org/10.1007/s00439-005-0119-4

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  • DOI: https://doi.org/10.1007/s00439-005-0119-4

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