Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
The mineralocorticoid aspect of severe 3β-HSD CAH is similar to those of 21-hydroxylase deficiency. Like other enzymes involved in early stages of both aldosterone and cortisol synthesis, the severe form of 3β-HSD deficiency can result in life-threatening salt-wasting in early infancy. Salt-wasting is managed acutely with saline and high-dose hydrocortisone, and long-term fludrocortisone.
The symptoms of isolated 17,20-lyase deficiency, in males, include pseudohermaphroditism (i.e., feminized, ambiguous, or mildly underdeveloped (e.g., micropenis, perineal hypospadias, and/or cryptorchidism (undescended testes)) external genitalia), female gender identity, and, in non-complete cases of deficiency where partial virilization occurs, gynecomastia up to Tanner stage V (due to low androgen levels, which results in a lack of suppression of estrogen); in females, amenorrhoea or, in cases of only partial deficiency, merely irregular menses, and enlarged cystic ovaries (due to excessive stimulation by high levels of gonadotropins); and in both sexes, hypergonadotropic hypogonadism (hypogonadism despite high levels of gonadotropins), delayed, impaired, or fully absent adrenarche and puberty with an associated reduction in or complete lack of development of secondary sexual characteristics (sexual infantilism), impaired fertility or complete sterility, tall stature (due to delayed epiphyseal closure), eunuchoid skeletal proportions, delayed or absent bone maturation, and osteoporosis.
Congenital adrenal hyperplasia due to 3β-hydroxysteroid dehydrogenase deficiency is an uncommon form of congenital adrenal hyperplasia (CAH) resulting from a mutation in the gene for one of the key enzymes in cortisol synthesis by the adrenal gland, 3β-hydroxysteroid dehydrogenase (3β-HSD) type II (HSD3B2). As a result, higher levels of 17OH-pregnenolone appear in the blood with adrenocorticotropic hormone (ACTH) challenge, which stimulates adrenal corticosteroid synthesis.
There is a wide spectrum of clinical presentations of 3β-HSD CAH, from mild to severe forms. The uncommon severe form results from a complete loss of enzymatic activity and manifests itself in infancy as salt wasting due to the loss of mineralocorticoids. Milder forms resulting from incomplete loss of 3β-HSD type II function do not present with adrenal crisis, but can still produce virilization of genetically female infants and undervirilization of genetically male infants. As a result, this form of primary hypoadrenalism is the only form of CAH that can cause ambiguous genitalia in both genetic sexes.
The excessive amounts of adrenal testosterone produce little effect on the genitalia of male infants with severe CAH. If a male infant with CAH is not detected by newborn screening, he will appear healthy and normal and be quickly discharged home to his family.
However, the lack of aldosterone results in a high rate of sodium loss in the urine. Urinary sodium concentrations may exceed 50 mEq/L. With this rate of salt loss, the infant cannot maintain blood volume, and hyponatremic dehydration begins to develop by the end of the first week of life. Potassium and acid excretion are also impaired when mineralocorticoid activity is deficient, and hyperkalemia and metabolic acidosis gradually develop. Ability to maintain circulation is further limited by the effect of cortisol deficiency. The early symptoms are spitting and poor weight gain, but most infants with severe CAH develop vomiting, severe dehydration, and circulatory collapse (shock) by the second or third week of life.
When brought to a hospital, the 1-3 week old infant will be both underweight and dehydrated by appearance. Blood pressure may be low. Basic chemistries will reveal hyponatremia, with a serum Na typically between 105 and 125 mEq/L. Hyperkalemia in these infants can be extreme—levels of K above 10 mEq/L are not unusual—as can the degree of metabolic acidosis. Hypoglycemia may be present. This is termed a salt-wasting crisis and rapidly causes death if not treated.
As ill as these infants can be, they respond rapidly to treatment with hydrocortisone and intravenous saline and dextrose quickly restores blood volume, blood pressure, and body sodium content, and reverses the hyperkalemia. With appropriate treatment, most infants are out of danger within 24 hours.
The symptoms of CAH vary depending upon the form of CAH and the sex of the patient. Symptoms can include:
Due to inadequate mineralocorticoids:
- vomiting due to salt-wasting leading to dehydration and death
Due to excess androgens:
- functional and average sized penis in cases involving extreme virilization (but no sperm)
- ambiguous genitalia, in some females, such that it can be initially difficult to identify external genitalia as "male" or "female".
- early pubic hair and rapid growth in childhood
- precocious puberty or failure of puberty to occur (sexual infantilism: absent or delayed puberty)
- excessive facial hair, virilization, and/or menstrual irregularity in adolescence
- infertility due to anovulation
- clitoromegaly, enlarged clitoris and shallow vagina
Due to insufficient androgens and estrogens:
- Undervirilization in XY males, which can result in apparently female external genitalia
- In females, hypogonadism can cause sexual infantilism or abnormal pubertal development, infertility, and other reproductive system abnormalities
Isolated 17,20-lyase deficiency (ILD), also called isolated 17,20-desmolase deficiency, is a rare endocrine and autosomal recessive genetic disorder which is characterized by a complete or partial loss of 17,20-lyase activity and, in turn, impaired production of the androgen and estrogen sex steroids. The condition manifests itself as pseudohermaphroditism (partially or fully underdeveloped genitalia) in males, in whom it is considered to be a form of intersex, and, in both sexes, as a reduced or absent puberty/lack of development of secondary sexual characteristics, resulting in a somewhat childlike appearance in adulthood (if left untreated).
Unlike the case of combined 17α-hydroxylase/17,20-lyase deficiency, isolated 17,20-lyase deficiency does not affect glucocorticoid production (or mineralocorticoid levels), and for that reason, does not result in adrenal hyperplasia or hypertension.
Mineralocorticoid manifestations of severe 11β-hydroxylase deficient CAH can be biphasic, changing from deficiency (salt-wasting) in early infancy to excess (hypertension) in childhood and adult life.
Salt-wasting in early infancy does not occur in most cases of 11β-OH CAH but can occur because of impaired production of aldosterone aggravated by inefficiency of salt conservation in early infancy. When it occurs it resembles the salt-wasting of severe 21-hydroxylase deficient CAH: poor weight gain and vomiting in the first weeks of life progress and culminate in life-threatening dehydration, hyponatremia, hyperkalemia, and metabolic acidosis in the first month.
Despite the inefficient production of aldosterone, the more characteristic mineralocorticoid effect of 11β-OH CAH is hypertension. Progressive adrenal hyperplasia due to persistent elevation of ACTH results in extreme overproduction of 11-deoxycorticosterone (DOC) by mid-childhood. DOC is a weak mineralocorticoid, but usually reaches high enough levels in this disease to cause effects of mineralocorticoid excess: salt retention, volume expansion, and hypertension.
Congenital adrenal hyperplasia (CAH) are any of several autosomal recessive diseases resulting from mutations of genes for enzymes mediating the biochemical steps of production of mineralocorticoids, glucocorticoids or sex steroids from cholesterol by the adrenal glands (steroidogenesis).
Most of these conditions involve excessive or deficient production of sex steroids and can alter development of primary or secondary sex characteristics in some affected infants, children, or adults.
Virilization of genetically female (XX) infants usually produces obvious genital ambiguity. Inside the pelvis, the ovaries are normal and since they have not been exposed to testicular antimullerian hormone (MIF), the uterus, fallopian tubes, upper vagina, and other mullerian structures are normally formed as well. However, the high levels of testosterone in the blood can enlarge the phallus, partially or completely close the vaginal opening, enclose the urethral groove so that it opens at the base of the phallus, on the shaft or even at the tip like a boy. Testosterone can cause the labial skin to become as thin and rugated as a scrotum, but cannot produce palpable gonads (i.e., testes) in the folds.
Thus, depending on the severity of hyperandrogenism, a female infant can be mildly affected, obviously ambiguous, or so severely virilized as to appear to be a male. Andrea Prader devised the following Prader scale as a way of describing the degree of virilization.
- An infant at stage 1 has a mildly large clitoris and slightly reduced vaginal opening size. This degree may go unnoticed or may be simply assumed to be within normal variation.
- Stages 2 and 3 represent progressively more severe degrees of virilization. The genitalia are obviously abnormal to the eye, with a phallus intermediate in size and a small vaginal opening.
- Stage 4 looks more male than female, with an empty scrotum and a phallus the size of a normal penis, but not quite free enough of the perineum to be pulled onto the abdomen toward the umbilicus (i.e., what is termed a chordee in a male). The single small urethral/vaginal opening at the base or on the shaft of the phallus would be considered a hypospadias in a male. X-rays taken after dye injection into this opening reveal the internal connection with the upper vagina and uterus. This common opening can predispose to urinary obstruction and infection.
- Stage 5 denotes complete male virilization, with a normally formed penis with the urethral opening at or near the tip. The scrotum is normally formed but empty. The internal pelvic organs include normal ovaries and uterus, and the vagina connects internally with the urethra as in Stage 4. These infants are not visibly ambiguous, and are usually assumed to be ordinary boys with undescended testes. In most cases, the diagnosis of CAH is not suspected until signs of salt-wasting develop a week later.
When the genitalia are determined to be ambiguous at birth, CAH is one of the leading diagnostic possibilities. Evaluation reveals the presence of a uterus, extreme elevation of 17OHP, levels of testosterone approaching or exceeding the male range but low AMH levels. The karyotype is that of an ordinary female: 46,XX. With this information, the diagnosis of CAH is readily made and female sex confirmed.
Evaluation of ambiguous genitalia is described in detail elsewhere. In most cases it is possible to confirm and assign female sex within 12–36 hours of birth. The exception are the rare, completely virilized genetic females (Prader stage 5), who present the most challenging assignment and surgery dilemmas, discussed below.
When the degree of ambiguity is obvious, corrective surgery is usually offered and performed. As reconstructive surgery on infant genitalia has become a focus of controversy, the issues are described in more detail below.
An inborn error of steroid metabolism is an inborn error of metabolism due to defects in steroid metabolism.
A variety of conditions of abnormal steroidogenesis exist due to genetic mutations in the steroidogenic enzymes involved in the process, of which include:
- 18,20-Desmolase (P450scc) deficiency: blocks production of all steroid hormones from cholesterol
- 3β-Hydroxysteroid dehydrogenase type 2 deficiency: impairs progestogen and androgen metabolism; prevents the synthesis of estrogens, glucocorticoids, and mineralocorticoids; causes androgen deficiency in males and androgen excess in females
- Combined 17α-hydroxylase/17,20-lyase deficiency: impairs progestogen metabolism; prevents androgen, estrogen, and glucocorticoid synthesis; causes mineralocorticoid excess
- Isolated 17,20-lyase deficiency: prevents androgen and estrogen synthesis
- 21-Hydroxylase deficiency: prevents glucocorticoid and mineralocorticoid synthesis; causes androgen excess in females
- 11β-Hydroxylase type 1 deficiency: impairs glucocorticoid and mineralocorticoid metabolism; causes glucocorticoid deficiency and mineralocorticoid excess as well as androgen excess in females
- 11β-Hydroxylase type 2 deficiency: impairs corticosteroid metabolism; results in excessive mineralocorticoid activity
- 18-Hydroxylase deficiency: impairs mineralocorticoid metabolism; results in mineralocorticoid deficiency
- 18-Hydroxylase overactivity: impairs mineralocorticoid metabolism; results in mineralocorticoid excess
- 17β-Hydroxysteroid dehydrogenase deficiency: impairs androgen and estrogen metabolism; results in androgen deficiency in males and androgen excess and estrogen deficiency in females
- 5α-Reductase type 2 deficiency: prevents the conversion of testosterone to dihydrotestosterone; causes androgen deficiency in males
- Aromatase deficiency: prevents estrogen synthesis; causes androgen excess in females
- Aromatase excess: causes excessive conversion of androgens to estrogens; results in estrogen excess in both sexes and androgen deficiency in males
In addition, several conditions of abnormal steroidogenesis due to genetic mutations in "receptors", as opposed to enzymes, also exist, including:
- Gonadotropin-releasing hormone (GnRH) insensitivity: prevents synthesis of sex steroids by the gonads in both sexes
- Follicle-stimulating (FSH) hormone insensitivity: prevents synthesis of sex steroids by the gonads in females; merely causes problems with fertility in males
- Luteinizing hormone (LH) insensitivity: prevents synthesis of sex steroids by the gonads in males; merely causes problems with fertility in females
- Luteinizing hormone (LH) oversensitivity: causes androgen excess in males, resulting in precocious puberty; females are asymptomatic
No activating mutations of the GnRH receptor in humans have been described in the medical literature, and only one of the FSH receptor has been described, which presented as asymptomatic.
Congenital adrenal hyperplasia due to 17α-hydroxylase deficiency is an uncommon form of congenital adrenal hyperplasia resulting from a defect in the gene CYP17A1, which encodes for the enzyme 17α-hydroxylase. It produces decreased synthesis of both cortisol and sex steroids, with resulting increase in mineralocorticoid production. Thus, common symptoms include mild hypocortisolism, ambiguous genitalia in genetic males or failure of the ovaries to function at puberty in genetic females, and hypokalemic hypertension (respectively). However, partial (incomplete) deficiency is notable for having inconsistent symptoms between patients, and affected genetic (XX) females may be wholly asymptomatic except for infertility.
Examples of symptoms of hypogonadism include delayed, reduced, or absent puberty, low libido, and infertility.
If the cause can be traced to the hypothalamus or pituitary, the cause is considered central. Other names for this type are "complete" or "true precocious" puberty.
Causes of central precocious puberty can include:
- damage to the inhibitory system of the brain (due to infection, trauma, or irradiation),
- hypothalamic hamartoma produces pulsatile gonadotropin-releasing hormone (GnRH),
- Langerhans cell histiocytosis, or
- McCune–Albright syndrome.
Central precocious puberty can be caused by intracranial neoplasm, infection (most commonly central nervous system tuberculosis especially in developing countries), trauma, hydrocephalus, and Angelman syndrome. Precocious puberty is associated with advancement in bone age, which leads to early fusion of epiphyses, thus resulting in reduced final height and short stature.
Precocious puberty can make a child fertile when very young, with the youngest mother on record being Lina Medina, who gave birth at the age of 5 years, 7 months and 17 days, in one report and at 6 years 5 months in another.
"Central precocious puberty (CPP) was reported in some patients with suprasellar arachnoid cysts (SAC), and SCFE (slipped capital femoral epiphysis) occurs in patients with CPP because of rapid growth and changes of growth hormone secretion."
If no cause can be identified, it is considered idiopathic or constitutional.
Secondary sexual development induced by sex steroids from other abnormal sources is referred to as "peripheral precocious puberty" or "precocious pseudopuberty." It typically presents as a severe form of disease with children. Symptoms are usually as a sequelae from adrenal insufficiency (because of 21-hydroxylase deficiency or 11-beta hydroxylase deficiency, the former being more common), which includes but is not limited to hypertension, hypotension, electrolyte abnormalities, ambiguous genitalia in females, signs of virilization in females. Blood tests will typically reveal high level of androgens with low levels of cortisol.
Causes can include:
- Endogenous sources
- gonadal tumors (such as arrhenoblastoma),
- adrenal tumors,
- germ cell tumor,
- congenital adrenal hyperplasia,
- McCune–Albright syndrome,
- Exogenous hormones
- Environmental exogenous hormones,
- As treatment for another condition.
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).
Glucocorticoid remediable aldosteronism (GRA), also describable as "aldosterone synthase hyperactivity", is an autosomal dominant disorder in which the increase in aldosterone secretion produced by ACTH is no longer transient.
It is a cause of primary hyperaldosteronism.
Congenital adrenal hyperplasia due to 11β-hydroxylase deficiency is a form of congenital adrenal hyperplasia (CAH) which produces a higher than normal amount of androgen, resulting from a defect in the gene encoding the enzyme steroid 11β-hydroxylase which mediates the final step of cortisol synthesis in the adrenal. 11β-OH CAH results in hypertension due to excessive mineralocorticoid effects. It also causes excessive androgen production both before and after birth and can virilize a genetically female fetus or a child of either sex.
Hirsutism is excessive body hair in men and women on parts of the body where hair is normally absent or minimal, such as on the chin or chest in particular, or the face or body in general. It may refer to a male pattern of hair growth that may be a sign of a more serious medical condition, especially if it develops well after puberty. It can be caused by increased levels of androgen hormones. The amount and location of the hair is measured by a Ferriman-Gallwey score. It is different than hypertrichosis, which is excessive hair growth anywhere on the body.
Hirsutism is usually the result of an underlying endocrine imbalance, which may be adrenal, ovarian, or central. Hirsutism is a commonly presenting symptom in dermatology, endocrinology, and gynecology clinics, and one that is considered to be the cause of much psychological distress and social difficulty. Facial hirsutism often leads to the avoidance of social situations and to symptoms of anxiety and depression.
Hirsutism affects between 5–15% of all women across all ethnic backgrounds. Depending on the definition and the underlying data, estimates indicate that approximately 40% of women have some degree of unwanted facial hair.
Although production of cortisol is inefficient enough to normalize ACTH, the 50-100-fold elevations of corticosterone have enough weak glucocorticoid activity to prevent glucocorticoid deficiency and adrenal crisis.
Patients with GRA may be asymptomatic, but the following symptoms can be present:
- Fatigue
- Headache
- High blood pressure
- Hypokalemia
- Intermittent or temporary paralysis
- Muscle spasms
- Muscle weakness
- Numbness
- Polyuria
- Polydipsia
- Tingling
- Hypernatraemia
- Metabolic alkalosis
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.
A variety of neurological symptoms have been associated with carnosinemia. They include: hypotonia, developmental delay, mental retardation, degeneration of axons, sensory neuropathy, tremors, demyelinization, gray matter anomalies, myoclonic seizures, and loss of purkinje fibers.
Many signs are associated with PPID, but only a subset of these are displayed in any single horse. Some horses may present with chronic laminitis without other overt signs of the disease.
- Hypertrichosis (hirsutisim) produces a long, thick, wavy coat that often has delayed shedding or fails to shed completely, and may lighten in color. Hirsutism has been suggested to be pathognomonic for PPID, with up to 95% of horses having PPID.
- Laminitis
- Increased drinking and increased urination
- Pot-bellied appearance
- Weight loss
- Redistribution of fat, leading to bulging supraorbital fat pad, a "cresty" neck, and fat over the tail head or in the sheath of males
- Lethargy
- Behavioral changes, often an increased docility
- Muscle wasting, especially along the top line
- Increased sweating, or less commonly, decreased sweating
- Increased appetite
- Decreased sensitivity to pain
- Recurrent infections due to immune impairment
- Rarely neurologic signs such as narcolepsy, blindness, or seizures
- Suspensary ligament degeneration
Dopamine beta (β)-hydroxylase deficiency is a condition that affects the autonomic nervous system (ANS). The ANS works via two opposing branches, the sympathetic and parasympathetic, both of which antagonistically control involuntary processes that regulate bodily homeostasis. Problems related to DβH deficiency often first appear as complications shortly after birth. Postnatal episodes may include vomiting, dehydration, hypotension, muscle hypotonia, hypothermia, and hypoglycemia.
Due to the deficiency of norepinephrine and epinephrine those affected by dopamine β-hydroxylase deficiency may present with droopy eyelids (ptosis), nasal congestion, and hypotension. The most common complaint of individuals with dopamine β-hydroxylase deficiency is orthostatic hypotension. The symptoms associated with orthostatic hypotension are dizziness, blurred vision, or fainting upon standing. Therefore, DβH deficiency patients may have an inability to stand for a prolonged period of time. This phenomenon is especially pronounced when going from supine to upright positions, such as getting out of bed in the morning. It is also worsened by extreme climates due to loss of fluid through excessive sweating. The inability to maintain normal blood pressure makes it difficult for people with DβH deficiency to exercise (exercise intolerance). Males with DβH deficiency may experience retrograde ejaculation, a discharge of semen backward into the bladder due to dysmotility of their smooth muscle, which as innervated by the ANS. A subset of DβH deficiency patients present with hypermobility. Postural orthostatic tachycardia syndrome, another form of dysautonomia, also sees this comorbidity with hypermobility in the form of a rare connective tissue disorder called Ehlers Danlos syndrome.
Another commonly experienced symptom is hypoglycemia, which is thought to be caused by adrenomedullary failure. In looking at the cardiovascular system, a loss of noradrenergic control is seen as T-wave abnormalities on electrocardiogram. Prolactin is frequently suppressed by excessive dopamine found in the patient's central nervous system. Excess dopamine can also affect digestion, producing vomiting and inhibiting motor signaling to the GI tract.
Dopamine beta (β)-hydroxylase deficiency (DβH deficiency) is a condition involving inadequate Dopamine beta-hydroxylase. It is characterized by increased amounts of serum dopamine and the absence of norepinephrine (NE) and epinephrine. Dopamine is released, as a false neurotransmitter, in place of norepinephrine. Other names for norepinephrine include noradrenaline (NA) and noradrenalin. This condition is also sometimes referred to as "norepinephrine deficiency". Researchers of disorders such as depression, schizophrenia, and migraines are very interested in studying this disorder, as patients with these specific diseases generally have a threefold increase in the amount of dopamine in their system and yet are generally normal. This is in contrast to patients with DβH deficiency.
Dopamine beta-hydroxylase deficiency is a very rare form of dysautonomia. It belongs to the class of rare diseases, with "a prevalence of fewer than 20 affected individuals, all of Western European descent", as described in the scientific literature. It is an caused by a mutation in the DβH gene, which results in the production of a nonfunctional dopamine β-hydroxylase enzyme. Without this enzyme, the patients with DβH deficiency end up having a large number of clinical manifestations which greatly affect their daily lives.