Extreme skewing of X chromosome inactivation in mothers of homosexual men

Sven Bocklandt; Steve Horvath; Eric Vilain; Dean H Hamer

doi:10.1007/s00439-005-0119-4

Extreme skewing of X chromosome inactivation in mothers of homosexual men

Hum Genet. 2006 Feb;118(6):691-4. doi: 10.1007/s00439-005-0119-4. Epub 2005 Dec 21.

Authors

Sven Bocklandt¹, Steve Horvath, Eric Vilain, Dean H Hamer

Affiliation

¹ Department of Human Genetics, University of California-Los Angeles, Los Angeles, CA, USA. sbocklandt@mednet.ucla.edu

PMID: 16369763
DOI: 10.1007/s00439-005-0119-4

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.

Publication types

Comparative Study

MeSH terms

Case-Control Studies
Chromosomes, Human, X*
Female
Fragile X Mental Retardation Protein / genetics
Homosexuality, Male / genetics*
Humans
Male
Mothers*
Receptors, Androgen / genetics
Statistics as Topic
X Chromosome Inactivation*

Substances

FMR1 protein, human
Receptors, Androgen
Fragile X Mental Retardation Protein