'Sexual differentiation is a dynamic process that is subject to a sequential program. The program is so ordered that it can be carried to completion in consecutive stages, often described as 1.) the establishment of chromosomal sex at fertilization, 2.) the development of gonadal sex, and 3.) the development of secondary sexual characteristics, collectively called the sexual phenotype. However, recent research has shown that sex differences are present immediately after fertilization, thus suggesting that sexual development be considered to include a stage of pregonadal sexual dimorphism.
....
In 1959, four reports demonstrated the crucial role of the Y chromosome in sex determination in mammals: Welshons and Russell (1959) showed that XO mice are females; Jacobs and Strong (1959) showed karyotype 47,XXY results in a male with Klinefelter syndrome; Ford and colleagues (1959b) reported the 45, XO karyotype in a woman with Turner syndrome; and Ford and colleagues (1959a) described two supernumerary chromosomes (an X and a 21, giving the karyotype 48,XXY+21) in a male with Klinefelter and Down syndromes.
These observations demonstrated that the presence of a Y chromosome, independent of the number of X chromosomes, resulted in the development of a mammalian embryo as a male, whereas in the absence of the Y chromosome, it developed as a female.
Thus, the Y chromosome appeared tom possess a gene or genes whose presence or absence determined the destiny of the bipotential gonad as a testis or ovary, respectively. Once the choice was made, gonadal hormones (and paracrine substances) would control the development of the dimorphic secondary characteristics.'
(Erickson RP, The Sex Determining Pathway, in Inborn Errors of Development: The Molecular Basis of Clinical Disorders of Morphogenesis, Ch. 15)
So media cherry-picking fails. Every potentially mutilated tranny should be vetted for Down, Turner, and Klinefelter syndromes.
