People with Laron syndrome have strikingly low rates of cancer and diabetes, although they appear to be at increased risk of accidental death due to their stature.

A male with pseudohypoparathyroidism has a 50% chance of passing on the defective GNAS gene to his children, although in an imprinted, inactive form. Any of his children receiving this gene will have pseudopseudohypoparathyroidism. Any of his daughters that have pseudopseudohypoparathyroidism may in turn pass along pseudohypoparathyroidism 1A to her children as the imprinting pattern on the inherited paternal gene will be changed to the maternal pattern in the mother's ovum during meiosis. The gene will be reactivated in any children who inherit it.

Pseudopseudohypoparathyroidism and pseudohypoparathyroidism both involve the same GNAS gene, but pseudopseudohypoparathyroidism has normal calcium homeostasis because of the normal maternal allele in the kidney.

The incidence of idiopathic GHD in infants is about 1 in every 3800 live births, and rates in older children are rising as more children survive childhood cancers which are treated with radiotherapy, although exact rates are hard to obtain.

The incidence of genuine adult-onset GHD, normally due to pituitary tumours, is estimated at 10 per million.

Growth hormone deficiency in childhood commonly has no identifiable cause (idiopathic), and adult-onset GHD is commonly due to pituitary tumours and their treatment or to cranial irradiation. A more complete list of causes includes:

- mutations of specific genes (e.g., GHRHR, GH1)

- congenital diseases such as Prader-Willi syndrome, Turner syndrome, or short stature homeobox gene (SHOX) deficiency

- congenital malformations involving the pituitary (e.g., septo-optic dysplasia, posterior pituitary ectopia)

- chronic renal insufficiency

- intracranial tumors in or near the sella turcica, especially craniopharyngioma

- damage to the pituitary from radiation therapy to the head (e.g. for leukemia or brain tumors), from surgery, from trauma, or from intracranial disease (e.g. hydrocephalus)

- autoimmune inflammation (hypophysitis)

- ischemic or hemorrhagic infarction from low blood pressure (Sheehan syndrome) or hemorrhage pituitary apoplexy

There are a variety of rare diseases which resemble GH deficiency, including the childhood growth failure, facial appearance, delayed bone age, and low IGF levels. However, GH testing elicits normal or high levels of GH in the blood, demonstrating that the problem is not due to a deficiency of GH but rather to a reduced sensitivity to its action. Insensitivity to GH is traditionally termed Laron dwarfism, but over the last 15 years many different types of GH resistance have been identified, primarily involving mutations of the GH binding protein or receptors.

Treatments focuses on symptoms, with genetic counseling recommended.

Molecular genetic investigations have shown that this disorder is mainly associated with mutations in the gene for the GH receptor. These can result in defective hormone binding to the ectodomain or reduced efficiency of dimerization of the receptor after hormone occupancy. There are exceptionally low levels of insulin-like growth factor (IGF-1) and its principal carrier protein, insulin-like growth factor binding protein 3.

A related condition involving postreceptor insensitivity to growth hormone has been associated with STAT5B.

Pseudohypoparathyroidism is a condition associated primarily with resistance to the parathyroid hormone. Those with the condition have a low serum calcium and high phosphate, but the parathyroid hormone level (PTH) is appropriately high (due to the low level of calcium in the blood). Its pathogenesis has been linked to dysfunctional G Proteins (in particular, Gs alpha subunit). The condition is extremely rare, with an estimated overall prevalence of 7.2/1,000,000 or approximately 1/140000.

The decision to treat is based on a belief that the child will be disabled by being extremely short as an adult, so that the risks of treatment (including sudden death) will outweigh the risks of not treating the symptom of short stature. Although short children commonly report being teased about their height, most adults who are very short are not physically or psychologically disabled by their height. However, there is some evidence to suggest that there is an inverse linear relationship with height and with risk of suicide.

Treatment is expensive and requires many years of injections with human growth hormones. The result depends on the cause, but is typically an increase in final height of about taller than predicted. Thus, treatment takes a child who is expected to be much shorter than a typical adult and produces an adult who is still obviously shorter than average. For example, several years of successful treatment in a girl who is predicted to be as an adult may result in her being instead.

Increasing final height in children with short stature may be beneficial and could enhance health-related quality of life outcomes, barring troublesome side effects and excessive cost of treatments.

Types include:

While biochemically similar, type 1 and 2 disease may be distinguished by the differing urinary excretion of cyclic AMP in response to exogenous PTH.

Some sources also refer to a "type 1c".

Shortness in children and young adults nearly always results from below-average growth in childhood, while shortness in older adults usually results from loss of height due to kyphosis of the spine or collapsed vertebrae from osteoporosis.

From a medical perspective, severe shortness can be a variation of normal, resulting from the interplay of multiple familial genes. It can also be due to one or more of many abnormal conditions, such as chronic (prolonged) hormone deficiency, malnutrition, disease of a major organ system, mistreatment, treatment with certain drugs, chromosomal deletions. Human growth hormone (HGH) deficiency may occur at any time during infancy or childhood, with the most obvious sign being a noticeable slowing of growth. The deficiency may be genetic. Among children without growth hormone deficiency, short stature may be caused by Turner syndrome, chronic renal insufficiency, being small for gestational age at birth, Prader–Willi syndrome, Wiedemann-Steiner syndrome, or other conditions. Genetic skeletal dysplasias also known as osteochondrodysplasia usually manifest in short stature.

When the cause is unknown, it is called "idiopathic short stature".

Short stature can also be caused by the bone plates fusing at an earlier age than normal, therefore stunting growth. Normally, your bone age is the same as your biological age but for some people, it is older. For many people with advanced bone ages, they hit a growth spurt early on which propels them to average height but stop growing at an earlier age. However, in some cases, people who are naturally shorter combined with their advanced bone age, end up being even shorter than the height they normally would have been because of their stunted growth.

Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are two different substances that have been identified as influencing growth plate formation and bone growth and, therefore, gigantism. The specific mechanisms of these are still not completely understood.

More broadly, GH and IGF have both been identified to be involved most stages of growth: embryonic, prenatal, and postnatal. Moreover, the receptor gene for IGF has been shown to be particularly influential throughout various stages of development, especially prenatally. This is the same for GH receptor genes which have been known to drive overall growth throughout various pathways.

Growth hormone is a precursor (upstream) of IGF-I, but each have their own independent roles in hormonal pathways. Although, both seem to ultimately come together to have a joint effect on growth.

Finding a specific genetic cause for gigantism has proven to be difficult. Gigantism is the primary example of growth hormone hyper-secretion disorders, a group of illnesses that are not yet deeply understood.

Some common mutations (errors in DNA) have been associated with gigantism. Pediatric gigantism patients have shown to have duplications of genes on a specific chromosome, Xq26. Typically, these patients also experienced an onset of typical gigantism symptoms before reaching the age of 5. This indicates a possible linkage between gene duplications and the gigantism.

Additionally, DNA mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene are common in gigantism patients. They have been found to be present in about 29 percent of patients with gigantism. AIP is labeled as a tumor suppressor gene and a pituitary adenoma disposition gene.

Mutations in AIP sequencing can have deleterious effects by inducing the development of pituitary adenomas which in turn can cause gigantism.

Two specific mutations in the AIP gene have been identified as possible causes of pituitary adenomas. These mutations also have the ability to cause adenoma growth to occur early in life. This is typical in gigantism.

Additionally, a large variety of other known genetic disorders have been found to influence the development of gigantism such as multiple endocrine neoplasia type 1 and 4, McCune-Albright syndrome, Carney complex, familial isolated pituitary adenoma, X-linked acrogigantism (X-LAG).

Although various gene mutations have been associated with gigantism, over 50 percent of cases cannot be linked to genetic causes, showing the complex nature of the disorder.

Familial acanthosis may arise as a result of an autosomal dominant trait, presenting at birth or developing during childhood.

Causes of HAIR-AN syndrome are not yet discovered or are not specifically known. But depending on some tests and data collected, HAIR-AN syndrome is thought to be caused by "both genetic and environmental" conditions or factors. And although it might be uncertain of what particularly caused HAIR-AN syndrome, one could just go and find out how hyperandrogenism, insulin resistance and acanthosis nigricans are caused, as these three are the leading contributors to HAIR-AN syndrome, which indirectly signifies that HAIR-AN syndrome is caused by these three. Knowing the cause of these three might provide one with some useful data that connects or links with the causes of HAIR-AN syndrome. SAHA syndrome is also taken in consider among the source that cause HAIR-An syndrome.

Endocrine syndromes associated with acanthosis nigricans can develop in many conditions, particularly:

- starts with insulin resistance, such as diabetes mellitus and metabolic syndrome

- excess circulating androgens, particularly Cushing's disease, acromegaly, polycystic ovarian disease

- Addison's disease and hypothyroidism

- Rare diseases, including pinealoma, leprechaunism, lipoatrophic diabetes, pineal hyperplasia syndrome, pituitary basophilism, ovarian hyperthecosis, stromal luteoma, ovarian dermoid cysts, Prader-Willi syndrome, and Alstrom syndrome.

Acanthosis nigricans associated with endocrine dysfunction is more insidious in its onset, is less widespread, and the patients are often concurrently obese.

Many people with MDP syndrome are high achievers intellectually following careers in law, medicine and computing. A crucial point is that they do not have progeria and there is no evidence of accelerated intellectual decline with age in these patients. Equally life expectancy has not been shown to be reduced. Patients of 65 have been described in the literature and none of the patients are known to have malignancy. Therefore, there are many crucial differences with progeria and the name of progeroid in the title is confusing as this really refers to the lack of fat in the face and taut skin and not any intellectual or other age associated features.

Some males have had undescended testes but in all cases, whether or not this was corrected, they have hypogonadism (reduced function of the testes) and many may be infertile due to inadequate testicular development. In females normal periods have been observed.

Low testosterone will require testosterone replacement. In peri-pubertal males, adequate testosterone replacement is required for its anabolic affects such as growth and also the induction of puberty with high doses. This needs to be coordinated with growth hormone replacement (if given) to avoid early closure of the epitheses (ends of the bones) which would reduce height.

This disorder is present at birth, however, it may not be understood until several years after birth. Acrodysostosis affects males and females in almost similar numbers. It is difficult to determine the frequency of acrodysostosis in the population as many cases of this disorder cannot be diagnosed properly.

Thyroid hormone resistance syndrome is rare, incidence is variously quoted as 1 in 50,000 or 1 in 40,000 live births. More than 1000 individuals have been identified with thyroid hormone resistance, of which 85% had thyroid hormone beta receptor mutation.

Hirsutism can be caused by either an increased level of androgens, the male hormones, or an oversensitivity of hair follicles to androgens. Male hormones such as testosterone stimulate hair growth, increase size and intensify the growth and pigmentation of hair. Other symptoms associated with a high level of male hormones include acne, deepening of the voice, and increased muscle mass. The condition is called hyperandrogenism.

Growing evidence implicates high circulating levels of insulin in women for the development of hirsutism. This theory is speculated to be consistent with the observation that obese (and thus presumably insulin resistant hyperinsulinemic) women are at high risk of becoming hirsute. Further, treatments that lower insulin levels will lead to a reduction in hirsutism.

It is speculated that insulin, at high enough concentration, stimulates the ovarian theca cells to produce androgens. There may also be an effect of high levels of insulin to activate insulin-like growth factor 1 (IGF-1) receptor in those same cells. Again, the result is increased androgen production.

Signs that are suggestive of an androgen-secreting tumor in a patient with hirsutism is rapid onset, virilization and palpable abdominal mass.

The following are conditions and situations that have been associated with hyperandrogenism and hence hirsutism in women:

- Hyperinsulinemia (insulin excess) or hypoinsulinemia (insulin deficiency or resistance as in diabetes).

- Ovarian cysts such as in polycystic ovary syndrome (PCOS), the most common cause in women.

- Ovarian tumors such as granulosa tumors, thecomas, Sertoli–Leydig cell tumors (androblastomas), and gynandroblastomas, as well as ovarian cancer.

- Hyperthecosis.

- Pregnancy.

- Adrenal gland tumors, adrenocortical adenomas, and adrenocortical carcinoma, as well as adrenal hyperplasia due to pituitary adenomas (as in Cushing's syndrome).

- hCG-secreting tumors

- Inborn errors of steroid metabolism such as in congenital adrenal hyperplasia, most commonly caused by 21-hydroxylase deficiency.

- Acromegaly and gigantism (growth hormone and IGF-1 excess), usually due to pituitary tumors.

- Use of certain medications such as androgens/anabolic steroids, phenytoin, and minoxidil.

Causes of hirsutism not related to hyperandrogenism include:

- Porphyria cutanea tarda.

- Minoxidil

Radiation exposure increases the risk of primary hyperparathyroidism. A number of genetic conditions including multiple endocrine neoplasia syndromes also increase the risk.

Estrogen insensitivity syndrome (EIS), or estrogen resistance, is a form of congenital estrogen deficiency or hypoestrogenism which is caused by a defective estrogen receptor (ER) – specifically, the estrogen receptor alpha (ERα) – that results in an inability of estrogen to mediate its biological effects in the body. Congenital estrogen deficiency can alternatively be caused by a defect in aromatase, the enzyme responsible for the biosynthesis of estrogens, a condition which is referred to as aromatase deficiency and is similar in symptomatology to EIS.

EIS is an extremely rare occurrence. As of 2016, there have been three published reports of EIS, involving a total of five individuals. The reports include a male case published in 1994, a female case published in 2013, and a familial case involving two sisters and a brother which was published in 2016.

EIS is analogous to androgen insensitivity syndrome (AIS), a condition in which the androgen receptor (AR) is defective and insensitive to androgens, such as testosterone and dihydrotestosterone (DHT). The functional opposite of EIS is hyperestrogenism, for instance that seen in aromatase excess syndrome.

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).

Hirsutism affects members of any gender, since rising androgen levels can cause excessive body hair, particularly in locations where women normally do not develop terminal hair during puberty (chest, abdomen, back, and face). The medical term for excessive hair growth that affects any gender is hypertrichosis.

In contrast to EIS, androgen insensitivity syndrome (AIS), a condition in which the androgen receptor (AR) is defective, is relatively common. This can be explained by the genetics of each syndrome. AIS is a X-linked recessive condition and thus carried over, by females, into future generations (although the most severe form, complete androgen insensitivity syndrome (CAIS), results in sterility, and hence cannot be passed on to offspring). EIS is not compatible with reproduction, thus each occurrence in humans would have to be a "de novo" mutation and is not transmitted to offspring.