male syndrome expressers may develop breasts, and those with swyer syndrome may have facial hair. klinefelter syndrome inherit a normal y chromosome and multiple x chromosomes, giving persons a karyotype of xxy persons with this are considered male swyer syndrome sry gene is transferred to the x chromosome instead of staying on the y chromosome, testis development will no longer occur characterized by an xy karyotype and female phenotype individuals have normally formed uteri and fallopian tubes, but the gonads are not functional xx male syndrome characterized by a body that has female chromosomes and sry attaches to one of them through translocation individuals have female genotype but male physical features while the presence or absence of sry has generally determined whether or not testis development occurs, it has been suggested that there are other factors that affect the functionality of sry. therefore, there are individuals who have the sry gene, but still develop as females, either because the gene itself is defective or mutated, or because one of the contributing factors is defective. this can happen in individuals exhibiting a xy, xxy, or xx sry-positive karyotype. additionally, other sex determining systems that rely on sry beyond xy are the processes that come after sry is present or absent in the development of an embryo. in a normal system, if sry is present for xy, sry will activate the medulla to develop gonads into testes. testosterone will then be produced and initiate the development of other male sexual characteristics. comparably, if sry is not present for xx, there will be a lack of the sry based on no y chromosome. the lack of sry will allow the cortex of embryonic gonads to develop in to ovaries, which will then produce estrogen, and lead to the development of other female sexual characteristics. role in other diseases sry has been shown to interact with the androgen receptor and individuals with xy karyotype and a functional sry gene can have an outwardly female phenotype due to an underlying androgen insensitivity syndrome (ais). individuals with ais are unable to respond to androgens properly due to a defect in their androgen receptor gene, and affected individuals can have complete or partial ais. sry has also been linked to the fact that males are more likely than females to develop dopamine-related diseases such as schizophrenia and parkinson's disease. sry encodes a protein that controls the concentration of dopamine, the neurotransmitter that carries signals from the brain that control movement and coordination. research in mice has shown that a mutation in sox10, an sry encoded transcription factor, is linked to the condition of dominant megacolon in mice. this mouse model is being used to investigate the link between sry and hirschsprung disease, or congenital megacolon in humans. there is also a link between sry encoded transcription factor sox9 and campomelic dysplasia (cd). this missense mutation causes defective chondrogenesis, or the process of cartilage formation, and manifests as skeletal cd. two thirds of 46,xy individuals diagnosed with cd have fluctuating amounts of male-to-female sex reversal. use in olympic screening further information: sex verification in sports one of the most controversial uses of this discovery was as a means for gender verification at the olympic games, under a system implemented by the international olympic committee in 1992. athletes with an sry gene were not permitted to participate as females, although all athletes in whom this was "detected" at the 1996 summer olympics were ruled false positives and were not disqualified. specifically, eight female participants (out of a total of 3387) at these games were found to have the sry gene. however, after further investigation of their genetic conditions, all these athletes were verified as female and allowed to compete. these athletes were found to have either partial or full androgen insensitivity, despite having an sry gene, making them phenotypically female. in the late 1990s, a number of relevant professional societies in united states called for elimination of gender verification, including the american medical association, stating that the method used was uncertain and ineffective. chromosomal screening was eliminated as of the 2000 summer olympics, but this was later followed by other forms of testing based on hormone levels. ongoing research despite the progress made during the past several decades in the study of sex determination, the sry gene, and its protein, work is still being conducted to further understanding in these areas. there remain factors that need to be identified in the sex-determining molecular network, and the chromosomal changes involved in many other human sex-reversal cases are still unknown. scientists continue to search for additional sex-determining genes, using techniques such as microarray screening of the genital ridge genes at varying developmental stages, mutagenesis screens in mice for sex-reversal phenotypes, and identifying the genes that transcription factors act on using chromatin immunoprecipitation.