Department of Microbiology & Immunology
University of Illinois
It is not the absence of two X chromosomes that makes for a man rather than a woman. The Y chromosome contains a sex-determining gene (or genes), which functions during testis differentiation. Missense and frame-shift mutations result in XY females.
P. Berta, J.R. Hawkins, A.H. Sinclair, A. Taylor, et al., "Genetic evidence equating SRY and the testis-determining factor," Nature, 348, 448-50, 29 November 1990. (Imperial Cancer Research Fund, London; Institut Pasteur, Paris)
P. Koopman, A. Munsterberg, B. Capel, N. Vivian, R. Lovell-Badge, "Expression of a candidate sex-determining gene during mouse testis differentiation," Nature, 348, 450-2, 29 November 1990. (National Institute for Medical Research, Mill Hill, London)
R.J. Jager, M. Anvret, K. Hall, G. Scherer, "A human XY female with a frame shift mutation in the candidate testis-determining gene SRY," Nature, 348, 452-4, 29 November 1990. (University of Freiburg, Germany;...