[Recently had a conversation with a Genomic Professor about Intersex]Intersex is a biological anomaly that occurs in about .005% of the human population. The question arises "does intersex create a new gender?" and this is where this article will try to scientifically answer this question. Gender is a social construct in some regard that is based on the sex that you are. Therefore, they are essentially one in the same. However, gender is generally used as a descriptor for "masculine" or "feminine" (and obviously has linguistic purposes as in Hebrew).
Intersexuality (having both male and female characteristics) may be noticeable at birth or may become apparent after puberty. Intersexuality noticeable at birth may be classified as female or male pseudohermaphroditism or true hermaphroditism. Female pseudohermaphroditism, or female intersex, may be of the adrenal or nonadrenal type. The adrenal type develops because of an inborn error in the metabolism of the adrenal hormone cortisol that leads to an increased secretion of corticotropin (ACTH) and consequent excessive secretion of androgens (male sex hormones). (1)
Male pseudohermaphrodites are males with varying deficiencies of internal and external virilization. Most commonly, the male intersex has a markedly hypospadiac penis, undescended testes, a cleft scrotum, and an enlarged prostatic utricle; a complete uterus and fallopian tubes may be found, with the vagina opening into the posterior wall of the urethra. (Such persons are pseudohermaphrodites in that they do not have ovaries.) (2)
Klinefelter syndrome, Turner syndrome, and testicular feminization are intersexuality syndromes that become apparent prior to or after puberty. Klinefelter syndrome is a genetic disorder of males who have an extra sex chromosome(XXY) and subsequently are usually infertile, have small testes, and have enlarged breasts at the time of puberty.
Genetically, Intersexuality is a reduction or overproduction of a specific chromosome resulting in various biological (usually reproductive) anomalies. The concept of these Genetic Disorders are fascinating but it should produce a philosophical or cultural statement stating that we have more than two sexes. These intersexual cases are always either "more" female or male. They are never equally both or neither.
This has been a brief overview of the genetic side for Intersexuality. For more on why this issue arose please see the article on Matthew 19.