Precocious puberty
Encyclopedia
As a medical term, precocious puberty describes puberty
Puberty
Puberty is the process of physical changes by which a child's body matures into an adult body capable of reproduction, as initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy...

 occurring at an unusually early age. In most of these children, the process is normal in every respect except the unusually early age, and simply represents a variation
Human variability
Human variability, or human variation, is the range of possible values for any measurable characteristic, physical or mental, of human beings. Differences can be trivial or important, transient or permanent, voluntary or involuntary, congenital or acquired, genetic or environmental...

 of normal development
Human development (biology)
Human development is the process of growing to maturity. In biological terms, this entails growth from a one-celled zygote to an adult human being.- Biological development:...

. In a minority of children, the early development is triggered by a disease such as a tumor
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

 or injury
Brain injury
A brain injury is any injury occurring in the brain of a living organism. Brain injuries can be classified along several dimensions. Primary and secondary brain injury are ways to classify the injury processes that occur in brain injury, while focal and diffuse brain injury are ways to classify...

 of the brain
Human brain
The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...

. Even in instances where there is no disease, unusually early puberty can have adverse effects on social behavior and psychological development, can reduce adult height
Human height
Human height is the distance from the bottom of the feet to the top of the head in a human body standing erect.When populations share genetic background and environmental factors, average height is frequently characteristic within the group...

 potential, and may shift some lifelong health risks. Central precocious puberty can be treated by suppressing the pituitary hormone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

s that induce sex steroid
Sex steroid
Sex steroids, also known as gonadal steroids, are steroid hormones that interact with vertebrate androgen or estrogen receptors. Their effects are mediated by slow genomic mechanisms through nuclear receptors as well as by fast nongenomic mechanisms through membrane-associated receptors and...

 production.

The term is used with several slightly different meanings that are usually apparent from the context. In its broadest sense, and often simplified as early puberty, "precocious puberty" sometimes refers to any physical sex hormone
Sex steroid
Sex steroids, also known as gonadal steroids, are steroid hormones that interact with vertebrate androgen or estrogen receptors. Their effects are mediated by slow genomic mechanisms through nuclear receptors as well as by fast nongenomic mechanisms through membrane-associated receptors and...

 effect, due to any cause, occurring earlier than the usual age, especially when it is being considered as a medical problem. Stricter definitions of "precocity" may refer only to central puberty starting before a statistically specified age based on percentile in the population (e.g., 2.5 standard deviations below the population mean), on expert recommendations of ages at which there is more than a negligible chance of discovering an abnormal cause, or based on opinion as to the age at which early puberty may have adverse effects. A common definition for medical purposes is onset before 8 years in girls or 9 years in boys.

Types and causes

Pubertas praecox is the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 term used by physicians in the 19th century. Early pubic hair
Pubic hair
Pubic hair is hair in the frontal genital area, the crotch, and sometimes at the top of the inside of the legs; these areas form the pubic region....

, breast
Breast
The breast is the upper ventral region of the torso of a primate, in left and right sides, which in a female contains the mammary gland that secretes milk used to feed infants.Both men and women develop breasts from the same embryological tissues...

, or genital development may result from natural early maturation or from several other conditions.

Central

If the cause can be traced to the hypothalamus
Hypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...

 or pituitary, the cause is considered central.

Causes can include:
  • damage to the inhibitory system of the brain (due to infection
    Infection
    An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...

    , trauma
    Physical trauma
    Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...

    , or irradiation
    Irradiation
    Irradiation is the process by which an object is exposed to radiation. The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to...

    )
  • hypothalamic hamartoma produces pulsatile gonadotropin-releasing hormone
    Gonadotropin-releasing hormone
    Gonadotropin-releasing hormone , also known as Luteinizing-hormone-releasing hormone and luliberin, is a tropic peptide hormone responsible for the release of follicle-stimulating hormone and luteinizing hormone from the anterior pituitary. GnRH is synthesized and released from neurons within...

     (GnRH)
  • Langerhans cell histiocytosis
    Langerhans cell histiocytosis
    Langerhans cell Histiocytosis is a rare disease involving clonal proliferation of Langerhans cells, abnormal cells deriving from bone marrow and capable of migrating from skin to lymph nodes...

  • McCune-Albright syndrome
    McCune-Albright syndrome
    McCune–Albright syndrome, described in 1937 by Donovan James McCune and Fuller Albright, is a genetic disorder of bones, skin pigmentation and hormonal problems along with premature puberty.-Symptoms:...



Central precocious puberty can be caused by intracranial neoplasm, infection, trauma, hydrocephalus, and Angelman syndrome
Angelman syndrome
Angelman syndrome is a neuro-genetic disorder characterized by intellectual and developmental delay, sleep disturbance, seizures, jerky movements , frequent laughter or smiling, and usually a happy demeanor....

. Bones can be considered older in individuals with early puberty. Early puberty is marked by growth hormone problems resulting from various brain disorders. Precocious puberty can make a child able to conceive when very young; the youngest mother on record is Lina Medina
Lina Medina
Lina Medina is the youngest confirmed mother in medical history, giving birth at the age of five years, seven months and 17 days...

, who gave birth at the age of 5 years, 7 months and 21 days.

"Central precocious puberty (CPP) was reported in some patients with suprasellar arachnoid cysts(SAC) [3], and SCFE 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
Idiopathic
Idiopathic is an adjective used primarily in medicine meaning arising spontaneously or from an obscure or unknown cause. From Greek ἴδιος, idios + πάθος, pathos , it means approximately "a disease of its own kind". It is technically a term from nosology, the classification of disease...

 or constitutional.

Peripheral

Secondary sexual development induced by sex steroid
Sex steroid
Sex steroids, also known as gonadal steroids, are steroid hormones that interact with vertebrate androgen or estrogen receptors. Their effects are mediated by slow genomic mechanisms through nuclear receptors as well as by fast nongenomic mechanisms through membrane-associated receptors and...

s 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 17 hydroxylase deficiency, the former being more common) which includes and is not limited to: 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
    • gonad
      Gonad
      The gonad is the organ that makes gametes. The gonads in males are the testes and the gonads in females are the ovaries. The product, gametes, are haploid germ cells. For example, spermatozoon and egg cells are gametes...

      al tumors (such as arrhenoblastoma)
    • adrenal tumors
    • germ cell tumor
      Germ cell tumor
      A germ cell tumor is a neoplasm derived from germ cells. Germ cell tumors can be cancerous or non-cancerous tumors. Germ cells normally occur inside the gonads...

    • congenital adrenal hyperplasia
      Congenital adrenal hyperplasia
      Congenital adrenal hyperplasia refers to any of several autosomal recessive diseases resulting from mutations of genes for enzymes mediating the biochemical steps of production of cortisol from cholesterol by the adrenal glands ....

    • McCune–Albright syndrome
  • Exogenous hormones
    • Environmental exogenous hormones
      Environmental exogenous hormones
      Environmental exogenous estrogens, otherwise referred to as xenoestrogens, are endocrine disruptors, structurally similar to estrogens. Xenoestrogens are clinically significant because they can mimic the effects of endogenous estrogen and thus have been implicated in precocious puberty and other...

    • As treatment for another condition

Research

Many causes of early puberty are somewhat unclear, though girls who have a high-fat diet and are not physically active or are obese
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...

 are more likely to physically mature earlier. "Obese girls, defined as at least 10 kilograms (22 pounds) overweight, had an 80% chance of developing breasts before their ninth birthday and starting menstruation before age 12 – the western average for menstruation is about 12.7 years." Exposure to chemicals that mimic estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...

 (known as xenoestrogens) is a possible cause of early puberty in girls. Bisphenol A
Bisphenol A
Bisphenol A is an organic compound with two phenol functional groups. It is used to make polycarbonate plastic and epoxy resins, along with other applications....

 is a xenoestrogen found in hard plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...

s that has been shown to affect sexual development. "Factors other than obesity, however, perhaps genetic and/or environmental ones, are needed to explain the higher prevalence of early puberty in black versus white girls." While more girls are increasingly entering puberty at younger ages, new research indicates that some boys are actually starting later (delayed puberty
Delayed puberty
Puberty is described as delayed puberty with exceptions when an organism has passed the usual age of onset of puberty with no physical or hormonal signs that it is beginning. Puberty may be delayed for several years and still occur normally, in which case it is considered constitutional delay, a...

). "Increasing rates of obese and overweight children in the United States may be contributing to a later onset of puberty in boys, say researchers at the University of Michigan Health System."

High levels of beta-hCG in serum and cerebrospinal fluid
Cerebrospinal fluid
Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...

 observed in a 9-year-old boy suggest a pineal gland tumor. The tumor is called a chorionic gonadotropin
Gonadotropin
Gonadotropins are protein hormones secreted by gonadotrope cells of the pituitary gland of vertebrates. This is a family of proteins, which include the mammalian hormones follitropin , lutropin , placental chorionic gonadotropins hCG and eCG and chorionic gonadotropin , as well as at least two...

 secreting pineal tumor
. Radiography and chemotherapy reduced tumor and beta-hCG levels normalized.

In a study using neonatal melatonin on rats, results suggest that elevated melatonin could be responsible for some cases of early puberty.

Clinical and social significance

Medical evaluation is sometimes necessary to recognize the few children with serious conditions from the majority who have entered puberty early but are still medically normal. Early sexual development deserves evaluation because it may:
  1. induce early bone maturation and reduce eventual adult height
  2. indicate the presence of a tumor or other serious problem
  3. cause the child, particularly a girl, to become an object of adult sexual interest


Early puberty is believed to put girls at higher risk of sexual abuse
Child sexual abuse
Child sexual abuse is a form of child abuse in which an adult or older adolescent uses a child for sexual stimulation. Forms of child sexual abuse include asking or pressuring a child to engage in sexual activities , indecent exposure with intent to gratify their own sexual desires or to...

, unrelated to pedophilia
Pedophilia
As a medical diagnosis, pedophilia is defined as a psychiatric disorder in adults or late adolescents typically characterized by a primary or exclusive sexual interest in prepubescent children...

 because the child has developed secondary sex characteristic
Secondary sex characteristic
Secondary sex characteristics are features that distinguish the two sexes of a species, but that are not directly part of the reproductive system. They are believed to be the product of sexual selection for traits which give an individual an advantage over its rivals in courtship and aggressive...

s making her look mature. "Imagine being eight or nine years old and having men hit on you because you have breasts. Grown women have enough trouble dealing with unwanted sexual advances – imagine being in the fourth grade," stated a researcher. Early puberty also puts girls at a higher risk for teasing or bullying, mental health disorders and short stature as adults." Helping children control their weight is suggested to help delay puberty. Early puberty additionally puts girls at a "far greater" risk for breast cancer
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...

 later in life. Girls as young as 8 are increasingly starting to menstruate
Menstruation
Menstruation is the shedding of the uterine lining . It occurs on a regular basis in sexually reproductive-age females of certain mammal species. This article focuses on human menstruation.-Overview:...

, develop breasts and grow pubic and underarm hair; these "biological milestones" only typically occurred at 13 or older decades ago. Females of African ancestry are especially prone to early puberty. There are theories debating the trend of early puberty, but the exact causes are not known. "This is a review of what we know; it's absolutely superb," said Dr. Marion Kavanaugh-Lynch, an oncologist
Oncology
Oncology is a branch of medicine that deals with cancer...

 and director of the California Breast Cancer Research Program in Oakland, which directs tobacco tax proceeds to research projects. "The data indicates that if you get your first period before age 12, your risk of breast cancer is 50 percent higher than if you get it at age 16," said the report's author, a biologist
Biologist
A biologist is a scientist devoted to and producing results in biology through the study of life. Typically biologists study organisms and their relationship to their environment. Biologists involved in basic research attempt to discover underlying mechanisms that govern how organisms work...

 and also a cancer survivor. "For every year we could delay a girl's first menstrual period, we could prevent thousands of breast cancers."

Though boys face fewer problems upon early puberty than girls, early puberty is not always positive for boys; early sexual maturation in boys can be accompanied by increased aggressiveness due to the surge of hormones that affect them. Because they appear older than their peers, pubescent boys may face increased social pressure to conform to adult norms; society may view them as more emotionally advanced, despite the fact that their cognitive
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...

 and social development may lag behind their appearance. Studies have shown that early maturing boys are more likely to be sexually active and are more likely to participate in risky behaviors.

Diagnostic criteria

Studies indicate that breast development in girls and pubic hair in girls and boys are starting earlier than in previous generations. As a result, "early puberty" in children, particularly girls, as young as 9 and 10 is no longer considered abnormal, although it may be upsetting to parents and can be harmful to children who mature physically at a time when they are immature mentally.

No single age limit reliably separates normal from abnormal processes in children today, but the following age thresholds for evaluation will minimize the risk of missing a significant medical problem:
  • Breast development in boys before appearance of pubic hair or testicular
    Testicle
    The testicle is the male gonad in animals. Like the ovaries to which they are homologous, testes are components of both the reproductive system and the endocrine system...

     enlargement.
  • Pubic hair
    Pubic hair
    Pubic hair is hair in the frontal genital area, the crotch, and sometimes at the top of the inside of the legs; these areas form the pubic region....

     or genital enlargement (gonadarche
    Gonadarche
    Gonadarche refers to the earliest gonadal changes of puberty. In response to pituitary gonadotropins, the ovaries in girls and the testes in boys begin to grow and increase the production of the sex steroids, especially estradiol and testosterone....

    ) in boys with onset before 9.5 years.
  • Pubic hair (pubarche
    Pubarche
    Pubarche refers to the first appearance of pubic hair in a child. Pubarche is one of the physical changes of puberty but should not be equated with it since it may occur independently of complete puberty...

    ) before 8 or breast development (thelarche
    Thelarche
    Thelarche is the onset of secondary breast development, usually occurring at the beginning of puberty in girls. Its etymology is from Greek θηλή [tʰelḗ], “nipple” and ἀρχή [arkʰḗ], “beginning, onset”. Thelarche is usually noticed as a firm, tender lump directly under the centre of the nipple...

    ) in girls with onset before 7 years.
  • Menstruation
    Menstruation
    Menstruation is the shedding of the uterine lining . It occurs on a regular basis in sexually reproductive-age females of certain mammal species. This article focuses on human menstruation.-Overview:...

     (menarche
    Menarche
    Menarche is the first menstrual cycle, or first menstrual bleeding, in female human beings. From both social and medical perspectives it is often considered the central event of female puberty, as it signals the possibility of fertility....

    ) in girls before 10 years.

Treatment

One possible treatment is with anastrozole
Anastrozole
Anastrozole is an aromatase-inhibiting drug approved for treatment of breast cancer after surgery, as well as for metastasis in both pre and post-menopausal women. The severity of breast cancer is increased by estrogen, as sex hormones cause hyperplasia, and differentiation at estrogen receptor...

. Histrelin
Histrelin
Histrelin acetate is a nonapeptide analog of gonadotropin-releasing hormone with added potency. When present in the bloodstream, it acts on particular cells of the pituitary gland called gonadotropes. Histrelin stimulates these cells to release luteinizing hormone and follicle-stimulating hormone...

 acetate (Supprelin LA), Triptorelin or Leuprolide
Leuprolide
Leuprorelin or leuprolide acetate is a GnRH analog. Proper Sequence: Pyr-His-Trp-Ser-Tyr-D-Leu-Leu-Arg-Pro-NHEt - Mode of action:Leuprolide acts as an agonist at pituitary GnRH receptors...

, any GnRH agonists, may also be used. GnRH agonists stimulate the pituitary to release Follicle Stimulating Hormone (FSH) and Luteinizing Hormone
Luteinizing hormone
Luteinizing hormone is a hormone produced by the anterior pituitary gland. In females, an acute rise of LH called the LH surge triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell-stimulating hormone , it stimulates Leydig cell...

 (LH). However, when used regularly, GnRH agonists cause a decreased release of FSH and LH. GnRH produced by the hypothalamus is pulsatile, allowing for a physiologic release of FSH and LH.

See also

  • Premature menopause and premature ovarian failure
    Premature ovarian failure
    Premature Ovarian Failure , also known as premature ovarian insufficiency, primary ovarian insufficiency , premature menopause, hypergonadotropic hypogonadism, is the loss of function of the ovaries before age 40...

  • Lina Medina
    Lina Medina
    Lina Medina is the youngest confirmed mother in medical history, giving birth at the age of five years, seven months and 17 days...

     – youngest ever mother recorded in medical history
  • List of youngest birth mothers
  • Delayed puberty
    Delayed puberty
    Puberty is described as delayed puberty with exceptions when an organism has passed the usual age of onset of puberty with no physical or hormonal signs that it is beginning. Puberty may be delayed for several years and still occur normally, in which case it is considered constitutional delay, a...


External links

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