Individuals with CAIS are raised as females. They are born phenotypically female and almost always have a heterosexual female gender identity; the incidence of homosexuality in women with CAIS is thought to be less than unaffected women. However, at least two case studies have reported male gender identity in individuals with CAIS.

Challenges presented to people affected by this condition include: psychologically coming to terms with the condition, difficulties with sexual function, infertility. Long-term studies indicate that with appropriate medical and psychological treatment, women with CAIS can be satisfied with their sexual function and psychosexual development. CAIS women can lead active lives and expect a normal lifespan.

During embryogenesis, without any external influences for or against, the human reproductive system is intrinsically conditioned to give rise to a female reproductive organisation.

As a result, if a gonad cannot express its sexual identity via its hormones—as in gonadal dysgenesis—then the affected person, no matter whether their chromosomes are XY or XX, will develop external female genitalia. Internal female genitalia, primarily the uterus, may or may not be present depending on the cause of the disorder.

In both sexes, the commencement and progression of puberty require functional gonads that will work in harmony with the hypothalamic and pituitary glands to produce adequate hormones.

For this reason, in gonadal dysgenesis the accompanying hormonal failure also prevents the development of secondary sex characteristics in either sex, resulting in a sexually infantile female appearance and infertility.

This condition will occur if there is an absence of both Müllerian inhibiting factor and testosterone. The absence of testosterone will result in regression of the Wolffian ducts; normal male internal reproductive tracts will not develop. The absence of Müllerian inhibiting factor will allow the Müllerian ducts to differentiate into the oviducts and uterus. In sum, this individual will possess female-like internal and external reproductive characteristics, lacking secondary sex characteristics. The genotype may be either 45,XO, 46,XX or 46,XY.

Treatment includes androgen (testosterone) supplementation to artificially initiate puberty, testicular prosthetic implantation, and psychological support. Gender Dysphoria may result in anorchic individuals who are assigned male at birth and raised as male despite lacking the necessary masculinizing hormones during prenatal, childhood, and adolescent development. Anorchic individuals who have a female identity may be administered estrogen alone in place of testosterone as no androgen blockers are necessary due to the lack of gonads.

Gonadectomy at time of diagnosis is the current recommendation for PAIS if presenting with cryptorchidism, due to the high (50%) risk of germ cell malignancy. The risk of malignancy when testes are located intrascrotally is unknown; the current recommendation is to biopsy the testes at puberty, allowing investigation of at least 30 seminiferous tubules, with diagnosis preferably based on OCT3/4 immunohistochemistry, followed by regular examinations. Hormone replacement therapy is required after gonadectomy, and should be modulated over time to replicate the hormone levels naturally present in the body during the various stages of puberty. Artificially induced puberty results in the same, normal development of secondary sexual characteristics, growth spurt, and bone mineral accumulation. Women with PAIS may have a tendency towards bone mineralization deficiency, although this increase is thought to be less than is typically seen in CAIS, and is similarly managed.

XX gonadal dysgenesis is related to the Swyer syndrome inasmuch as both conditions have the same phenotype and clinical issues; however in Swyer syndrome the karyotype is 46,XY, and thus gonadectomy is recommended.

In Turner syndrome there is a demonstrable abnormality in or absence of one of the sex chromosomes that is the cause of the development of gonadal dysgenesis. In contrast XX gonadal dysgenesis has a normal female chromosome situation.

Another type of XX gonadal dysgenesis is known as 46,XX gonadal dysgenesis epibulbar dermoid, which follows the similar symptoms as the regular syndrome, though it also shows signs of epibulbar dermoid (eye disorder). It has been suggested to be a new type of syndrome.

In a normal situation, all the cells in an individual will have 46 chromosomes with one being an X and one a Y or with two Xs. However, sometimes during this complicated early copying process (DNA replication and cell division), one chromosome can be lost. In 45,X/46,XY, most or all of the Y chromosome is lost in one of the newly created cells. All the cells then made from this cell will lack the Y chromosome. All the cells created from the cells that have not lost the Y chromosome will be XY. The 46,XY cells will continue to multiply at the same time as the 45,X cells multiply. The embryo, then the fetus and then the baby will have what is called a 45,X/46,XY constitution. This is called a

mosaic karyotype because, like tiles in mosaic floors or walls, there is more than one type of cell.

There are many chromosomal variations that cause the 45,X/46,XY karyotype, including malformation (isodicentricism) of the Y chromosomes, deletions of Y chromosome or translocations of Y chromosome segments. These rearrangements of the Y chromosome can lead to partial expression of the SRY gene which may lead to abnormal genitals and testosterone levels.

Nuclear receptor subfamily 5 group A member 1 (NR5A1), also known as SF1 or Ad4BP (MIM 184757), is located on the long arm of chromosome 9 (9q33.3). The NR5A1 is an orphan nuclear receptor that was first identified following the search for a common regulator of the cytochrome P450 steroid hydroxylase enzyme family. This receptor is a pivotal transcriptional regulator of an array of genes involved in reproduction, steroidogenesis and male sexual differentiation and also plays a crucial role in adrenal gland formation in both sexes. NR5A1 regulates the mullerian inhibitory substance by binding to a conserved upstream regulatory element and directly participates in the process of mammalian sex determination through mullerian duct regression. Targeted disruption of NR5A1 (Ftzf1) in mice results in gonadal and adrenal agenesis, persistence of Mullerian structures and abnormalities of the hypothalamus and pituitary gonadotropes. Heterozygous animals demonstrate a milder phenotype including an impaired adrenal stress response and reduced testicular size. In humans, NR5A1 mutations were first described in patients with 46, XY karyotype and disorders of sex development (DSD), Mullerian structures and primary adrenal failure (MIM 612965). After that, heterozygous NR5A1 mutations were described in seven patients showing 46, XY karyotype and ambiguous genitalia, gonadal dysgenesis, but no adrenal insufficiency. Since then, studies have confirmed that mutations in NR5A1 in patients with 46, XY karyotype cause severe underandrogenisation, but no adrenal insufficiency, establishing dynamic and dosage-dependent actions for NR5A1. Subsequent studies revealed that NR5A1 heterozygous mutations cause primary ovarian insufficiency (MIM 612964).

Management of AIS is currently limited to symptomatic management; methods to correct a malfunctioning androgen receptor protein that result from an AR gene mutation are not currently available. Areas of management include sex assignment, genitoplasty, gonadectomy in relation to tumor risk, hormone replacement therapy, and genetic and psychological counseling.

There are several forms of gonadal dysgenesis. The term “pure gonadal dysgenesis” (PGD) has been used to describe conditions with normal sets of sex chromosomes (e.g., 46,XX or 46,XY), as opposed to those whose gonadal dysgenesis results from missing all or part of the second sex chromosome. The latter group includes those with Turner syndrome (i.e., 45,X) and its variants, as well as those with mixed gonadal dysgenesis and a mixture of cell lines, some containing a Y chromosome (e.g., 46,XY/45,X).

Thus Swyer syndrome is referred to as PGD, 46,XY, and XX gonadal dysgenesis as PGD, 46,XX. Patients with PGD have a normal karyotype but may have defects of a specific gene on a chromosome.

In 1951, Perrault reported the association of gonadal dysgenesis and deafness, now called Perrault syndrome.

Anorchia (or anorchism) is an XY disorder of sex development in which individuals have both testes absent at birth. Within a few weeks of fertilization, the embryo develops rudimentary gonads (testes), which produce hormones responsible for the development of the reproductive system. If the testes fail to develop within eight weeks, the baby will develop female genitalia (see Swyer syndrome). If the testes begin to develop but are lost or cease to function between eight and 10 weeks, the baby will have ambiguous genitalia when it is born. However, if the testes are lost after 14 weeks, the baby will have partial male genitalia with the notable absence of gonads.

Tests include observable lack of testes, low testosterone levels (typical female levels), elevated follicle stimulating hormone and luteinizing hormone levels, XY karyotype, ultrasound or magnetic resonance imaging showing absent gonadal tissue, low bone density, low anti-Müllerian hormone levels, and surgical exploration for evidence of male gonadal tissue.

About 10–15% of human couples are infertile, unable to conceive. In approximately in half of these cases, the underlying cause is related to the male. The underlying causative factors in the male infertility can be attributed to environmental toxins, systemic disorders such as, hypothalamic–pituitary disease, testicular cancers and germ-cell aplasia. Genetic factors including aneuploidies and single-gene mutations are also contributed to the male infertility. Patients suffering from nonobstructive azoospermia or oligozoospermia show microdeletions in the long arm of the Y chromosome and/or chromosomal abnormalities, each with the respective frequency of 9.7% and 13%. A large percentage of human male infertility is estimated to be caused by mutations in genes involved in primary or secondary spermatogenesis and sperm quality and function. Single-gene defects are the focus of most research carried out in this field.

NR5A1 mutations are associated with male infertility, suggesting the possibility that these mutations cause the infertility. However, it is possible that these mutations individually have no major effect and only contribute to the male infertility by collaboration with other contributors such as environmental factors and other genomics variants. Vice versa, existence of the other alleles could reduce the phenotypic effects of impaired NR5A1 proteins and attenuate the expression of abnormal phenotypes and manifest male infertility solely.

Encountered karyotypes include 47XXY, 46XX/46XY, or 46XX/47XXY or XX & XY with SRY Mutations, Mixed Chromosomal abnormalities or hormone deficiency/excess disorders, and various degrees of mosaicism of these and a variety of others. The 3 Primary Karyotypes for True Hermaphroditism are XX with genetic defects (55-70% of cases), XX/XY (20-30% of cases) & XY (5-15% of cases) with the remainder being a variety of other Chromosomal abnormalities and Mosaicisms.

Upon diagnosis, estrogen and progesterone therapy is typically commenced, promoting the development of female characteristics.

The consequences of streak gonads to a person with Swyer syndrome:

1. Gonads cannot make estrogen, so the breasts will not develop and the uterus will not grow and menstruate until estrogen is administered. This is often given transdermally.

2. Gonads cannot make progesterone, so menstrual periods will not be predictable until progestin is administered, usually as a pill.

3. Gonads cannot produce eggs so conceiving children naturally is not possible. A woman with a uterus and ovaries but without female gamete is able to become pregnant by implantation of another woman's fertilized egg (embryo transfer).

4. Streak gonads with Y chromosome-containing cells have a high likelihood of developing cancer, especially gonadoblastoma. Streak gonads are usually removed within a year or so of diagnosis since the cancer can begin during infancy.

There are several ways in which this may occur.

- It can be caused by the division of one ovum, followed by fertilization of each haploid ovum and fusion of the two zygotes early in development.

- Alternately, an ovum can be fertilized by two sperm followed by trisomic rescue in one or more daughter cells.

- Two ova fertilized by two sperm will occasionally fuse to form a tetragametic chimera. If one male zygote and one female zygote fuse, a hermaphroditic individual may result.

- It can be associated with mutation in the SRY gene.

45,X/46,XY mosaicism, also known as X0/XY mosaicism and mixed gonadal dysgenesis, is a rare disorder of sex development in humans associated with sex chromosome aneuploidy and mosaicism of the Y chromosome. This is called a mosaic karyotype because, like tiles in mosaic floors or walls, there is more than one type of cell.

The clinical manifestations are highly variable, ranging from partial virilisation and ambiguous genitalia at birth, to patients with a completely male or female gonads. Most individuals with this karyotype have apparently normal male genitalia, and a minority with female genitalia, with a significant number of individuals showing genital abnormalities or intersex characteristics. A significantly higher than normal number of other developmental abnormalities are also found in individuals with X0/XY mosaicism. Psychomotor development is normal.

Many myths are given regarding the possible causes of baldness and its relationship with one's virility, intelligence, ethnicity, job, social class, wealth, etc. While skepticism may be warranted in many cases due to a lack of scientific validation, some claims may have a degree of underlying truth and are supported by research.

A 50% chance exists for a person to share the same X chromosome as his maternal grandfather. Because women have two X chromosomes, they have two copies of the androgen receptor gene, while men only have one. However, a person with a balding father also has a significantly greater chance of experiencing hair loss.

Because it increases testosterone levels, many Internet forums have put forward the idea that weight training and other forms of exercise increase hair loss in predisposed individuals. Although scientific studies do support a correlation between exercise and testosterone, no direct study has found a link between exercise and baldness. However, a few have found a relationship between a sedentary life and baldness, suggesting some exercise is beneficial. The type or quantity of exercise may influence hair loss.

Testosterone levels are not a good marker of baldness, and many studies actually show paradoxical low testosterone in balding persons, although research on the implications is limited.

Emotional stress has been shown to accelerate baldness in genetically susceptible individuals.

Stress due to sleep deprivation in military recruits lowered testosterone levels, but is not noted to have affected SHBG. Thus, stress due to sleep deprivation in fit males is unlikely to elevate DHT, which is one cause of male pattern baldness. Whether sleep deprivation can cause hair loss by some other mechanism is not clear.

Levels of free testosterone are strongly linked to libido and DHT levels, but unless free testosterone is virtually nonexistent, levels have not been shown to affect virility. Men with androgenic alopecia are more likely to have a higher baseline of free androgens. However, sexual activity is multifactoral, and androgenic profile is not the only determining factor in baldness. Additionally, because hair loss is progressive and free testosterone declines with age, a male's hairline may be more indicative of his past than his present disposition.

Many misconceptions exist about what can help prevent hair loss, one of these being that lack of sexual activity will automatically prevent hair loss. While a proven direct correlation exists between increased frequency of ejaculation and increased levels of DHT, as shown in a recent study by Harvard Medical School, the study suggests that ejaculation frequency may be a sign, rather than a cause, of higher DHT levels. Another study shows that although sexual arousal and masturbation-induced orgasm increase testosterone concentration around orgasm, they reduce testosterone concentration on average (especially before abstinence) and because about 5% of testosterone is converted to DHT, ejaculation does not elevate DHT levels.

The only published study to test correlation between ejaculation frequency and baldness was probably large enough to detect an association (1390 subjects) and found no correlation, although persons with only vertex androgenetic alopecia had had fewer female sexual partners than those of other androgenetic alopecia categories (such as frontal or both frontal and vertex). One study may not be enough, especially in baldness, where there is a complex with age. Marital status has been shown in some studies to influence hair loss in cross-sectional studies (NHANES1).

Treatment of HH is usually with hormone replacement therapy, consisting of androgen and estrogen administration in males and females, respectively.

There are a multitude of different etiologies of HH. Congenital causes include the following:

- Chromosomal abnormalities (resulting in gonadal dysgenesis) - Turner's syndrome, Klinefelter's syndrome, Swyer's syndrome, XX gonadal dysgenesis, and mosaicism.

- Defects in the enzymes involved in the gonadal biosynthesis of the sex hormones - 17α-hydroxylase deficiency, 17,20-lyase deficiency, 17β-hydroxysteroid dehydrogenase III deficiency, and lipoid congenital adrenal hyperplasia.

- Gonadotropin resistance (e.g., due to inactivating mutations in the gonadotropin receptors) - Leydig cell hypoplasia (or insensitivity to LH) in males, FSH insensitivity in females, and LH and FSH resistance due to mutations in the "GNAS" gene (termed pseudohypoparathyroidism type 1A).

Acquired causes (due to damage to or dysfunction of the gonads) include ovarian torsion, vanishing/anorchia, orchitis, premature ovarian failure, ovarian resistance syndrome, trauma, surgery, autoimmunity, chemotherapy, radiation, infections (e.g., sexually-transmitted diseases), toxins (e.g., endocrine disruptors), and drugs (e.g., antiandrogens, opioids, alcohol).

One of the main characteristics of this disorder is adrenal insufficiency, which is a reduction in adrenal gland function resulting from incomplete development of the gland's outer layer (the adrenal cortex). Adrenal insufficiency typically begins in infancy or in childhood and can cause vomiting, difficulty with feeding, dehydration, extremely low blood sugar (hypoglycemia), low sodium levels, and shock. However, adult-onset cases have also been described. See also Addison's Disease.

Affected males may also lack male sex hormones, which leads to underdeveloped reproductive tissues, undescended testicles (cryptorchidism), delayed puberty, and an inability to father children (infertility). These characteristics are known as hypogonadotropic hypogonadism. Females are rarely affected by this disorder, but a few cases have been reported of adrenal insufficiency or a lack of female sex hormones, resulting in underdeveloped reproductive tissues, delayed puberty, and an absence of menstruation.

X-linked adrenal hypoplasia congenita is a genetic disorder that mainly affects males. It involves many endocrine tissues in the body, especially the adrenal glands.

Androgenic alopecia is typically experienced as a "moderately stressful condition that diminishes body image satisfaction". However, although most men regard baldness as an unwanted and distressing experience, they usually are able to cope and retain integrity of personality.

Although baldness is not as common in women as in men, the psychological effects of hair loss tend to be much greater. Typically, the frontal hairline is preserved, but the density of hair is decreased on all areas of the scalp. Previously, it was believed to be caused by testosterone just as in male baldness, but most women who lose hair have normal testosterone levels.

Cervical agenesis is estimated to occur in 1 in 80,000 females. It is often associated with deformity of the vagina; one study found that 48% of patients with cervical agenesis had a normal, functional vagina, while the rest of the cases were accompanied by vaginal hypoplasia.