Appendix A

 

Examples of Intersex Categories

The following list has been included not to try to prepare you for a medical degree but to help you see that the causes for ambiguities in sexual identity and genitalia are complex and varied as well as found on a wide spectrum of the gender continuum.

I. XY individuals that feminize or fail to masculinize

A. Lack SRY gene (normally found on short arm of Y chromosome)

B. Have SRY gene

1. Decreased androgen activity due to protein receptor abnormalities

a. Complete Testicular Feminization

b. Incomplete (Partial) Testicular Feminization

c. Reifenstein's Syndrome (appearance of both enlarged
                           mammary glands and male genitalia)

2. Increased estrogen activity

a. Abnormal pituitary hypersecretion of LH (ICSH) that leads to
                           testicular estrogen production

b. Testicular tumor

c. Increased estrogen-androgen ratio

d. Adrenal tumor

e. Aromatization (i.e., peripheral conversion) of secreted
                           androgens  (sometimes due to liver disease)

f. Decrease in peripheral conversion of testosterone to its active
                          metabolite, dihydrotestosterone

3. Male pseudohermaphroditism (with 5a-reductase deficiency)

These individuals are usually raised as girls. However, at puberty, breasts fail to develop, pubic hair and beard develop, menses does not occur, and external genitalia virilize (masculinize). By standards for girls at puberty, testosterone production is increased. These individuals often assume male gender roles after puberty. Sometimes referred to as Guevodoces.

 

II. XX individuals that masculinize or fail to feminize

A. Have SRY gene (translocated from Y to X during spermatogenesis)

B. Lack SRY gene

1. Female Pseudohermaphroditism

a. Exogenously-produced androgens (intrauterine exposure
                           during pregnancy)

1) hormone therapy

2) maternal ovarian production

3) maternal adrenal production

b. Endogenously-produced androgens

1) adrenal production (includes Adrenogenital Syndrome and
                              Congenital Adrenal Hyperplasia, or CAH)

2) ovarian production (for example, polycystic ovarian disease)

2. Sexual Infantilism due to 17-hydroxylase deficiency
                     (which mediates estrogen production)

3. Turner's Syndrome (has only 45 chromosomes: lacks a second
                     sex chromosome)

III. Hermaphroditism

A. Pseudohermaphroditism

B. True Hermaphroditism (true hermaphroditism requires the presence of
             ovarian as well as testicular tissue)

1. Mosaicism

    A mosaic is an organism that can arise from abnormal cell division of an
           XY or XXY individual during embryonic development.

2. Chimerism

A chimera is an offspring that results from the fusion of two or more
                  different zygotes.