http://www.isna.org/faq/ (General information about Intersex conditions. Feel free to explore other pages besides the FAQ page. The 10 myths section appeared to be very interesting)
http://www.ted.com/talks/alice_dreger_is_anatomy_destiny.html (A 19 minute talk that addresses the fact that the dividing lines about sex cannot be sharply drawn. The video appears to be abruptly cut off, but every version I found had the same length.)
http://www.biologicalpsychiatryjournal.com/article/S0006-3223(08)01087-1/abstract (abnormality in androgen receptors linked to MTF transsexualism)
http://humrep.oxfordjournals.org/content/21/3/579.full.pdf+html (A paper on the existence of chimera humans, the condition in which one person is born with cells from two different zygotes, including cases where both XX and XY chromosomes are present in the same person in this manner.)
http://ghr.nlm.nih.gov/condition/mayer-rokitansky-kuster-hauser-syndrome (National Institute of Health article about a syndrome that affects 1 in 4500 women to be born where the vagina, uterus and cervix are either missing or severely underdeveloped – plus some other physical abnormalities in some of the women affected by MRKH)
http://www.huffingtonpost.com/2013/11/14/jacqui-beck-no-vagina-mrkh_n_4274401.html?utm_hp_ref=email_share (Online article about a British teenager who discovered she was born without a vagina and suffers from MRKH)
http://www.denverpost.com/news/ci_20606569/colorado-transgender-photographer-focuses-family-identity (article on Stevie Crecelius – father of two children who learned from an ultrasound that there are female organs inside)
An article describing a condition in a remote village in the Dominican Republic known as “guevedoces” which affects 2% of the live births there. Children with this condition appear to be born female but “turn into” males at puberty. The cause is a deficiency in the enzyme 5-alpha Reductase. The prostate drug finasteride also inhibits this enzyme and shrinks the prostate without affecting the male physical traits.
An article describing a rare deficiency in a non-sex chromosome (autosome) which adversely affects testosterone biosynthesis, resulting in impaired virilization of genetically male children and excessive virilization of female adults. It is one of only a few sexual development disorders that can affect primary and/or secondary sexual characteristics of both males and females.
An overview of a deficiency that results in ambiguous genitalia in male infants, but can also affect female infants and adults who have a late-onset variant.
BRAIN STUDIES COMPARING BRAINS OF TRANSSEXUALS TO MALE OR FEMALE NORMS
Articles that I believe are peer-reviewed showing that MTF transsexual brains are more like the normative female brain than the male brain in structure:
REFERENCES TO STUDIES THAT SHOW THE RELATIONSHIP BETWEEN BRAIN STRUCTURE OR COMPOSITION AND GENDER IDENTITY
CASE STUDY OF XY NORMATIVE WOMAN ABLE TO GIVE UNASSISTED BIRTH
PROGRESSIVE CHRISTIAN THEOLOGICAL VIEW OF TRANSGENDER AND INTERSEX
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