|Classification and external resources|
In medicine, precocious puberty is puberty 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 of normal development. In a minority of children, the early development is triggered by a disease such as a tumor or injury of the brain. 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 potential, and may shift some lifelong health risks. Central precocious puberty can be treated by suppressing the pituitary hormones that induce sex steroid 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 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
Causes 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
- McCune-Albright syndrome
Central precocious puberty can be caused by intracranial neoplasm, infection, trauma, hydrocephalus, and Angelman syndrome. 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, 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), 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 17 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
- Exogenous hormones
- Environmental exogenous hormones
- As treatment for another condition
Isosexual and heterosexual
Sometimes a patient may develop in the opposite direction. For example, a male may develop breasts and other feminine characteristics, while a female may develop a deepened voice and facial hair. This is called heterosexual precocity. It is very rare in comparison to isosexual precocity and is usually the result of only unusual circumstances. As an example, children with a very rare genetic condition called familial hyperestrogenism in which exceptionally high circulating levels of estrogen are present usually develop precocious puberty. Males and females are hyperfeminized by the syndrome and, hence, the precocity is classified as heterosexual in the case of males.
Many causes of early puberty are somewhat unclear, though girls who have a high-fat diet and are not physically active or are obese are more likely to physically mature earlier. "Obese girls, defined as at least 10 kilograms (22 pounds) overweight, had an 80 percent 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 (known as xenoestrogens) is a possible cause of early puberty in girls. Bisphenol A, a xenoestrogen found in hard plastics, 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). "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 observed in a 9-year-old boy suggest a pineal gland tumor. The tumor is called a chorionic gonadotropin secreting pineal tumor. Radiotherapy 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.
Familial cases of idiopathic central precocious puberty (ICPP) have been reported, leading researchers to believe there are specific genetic modulators of ICPP. Mutations in genes such as LIN28, and LEP and LEPR, which encode leptin and the leptin receptor, have been associated with precocious puberty. The association between LIN28 and puberty timing was validated experimentally in vivo, when it was found that mice with ectopic overexpression of LIN28 show an extended period of pre-pubertal growth and a significant delay in puberty onset.
Mutations in the kisspeptin (KISS1) and its receptor, KISS1R (also known as GPR54), involved in GnRH secretion and puberty onset, are also thought to be the cause for ICPP  However, this is still a controversial area of research, and some investigators found no association of mutations in the LIN28 and KISS1/KISS1R genes to be the common cause underlying ICPP.
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 warrants evaluation because it may:
- induce early bone maturation and reduce eventual adult height;
- indicate the presence of a tumor or other serious problem;
- 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, unrelated to pedophilia because the child has developed secondary sex characteristics; however, a causal relationship is, as yet, inconclusive. 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 later in life. Girls as young as 8 are increasingly starting to menstruate, develop breasts and grow pubic and underarm hair; these "biological milestones" typically occurred only at 13 or older in decades past. 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.
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 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.
Studies indicate that breast development in girls and the appearance of 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 age reliably separates normal from abnormal processes in children, but the following age thresholds for evaluation are thought to minimize the risk of missing a significant medical problem:
- Breast development in boys before appearance of pubic hair or testicular enlargement.;
- Pubic hair or genital enlargement (gonadarche) in boys with onset before 9.5 years;
- Pubic hair (pubarche) before 8 or breast development (thelarche) in girls with onset before 7 years;
- Menstruation (menarche) in girls before 10 years.
One possible treatment is with anastrozole. Histrelin acetate (Supprelin LA), triptorelin or leuprolide, any GnRH agonists, may be used. Non-continuous usage of GnRH agonists stimulates the pituitary gland to release follicle stimulating hormone (FSH) and luteinizing hormone (LH). However, when used regularly, GnRH agonists cause a decreased release of FSH and LH. Prolonged use has a risk of causing osteoporosis. After stopping GnRH agonists, pubertal changes resume within 3 to 12 months.
- "Precocious Puberty". KidsHealth. Retrieved 2013-09-09.
- precocious puberty at the US National Library of Medicine Medical Subject Headings (MeSH)
- "precocious puberty" at Dorland's Medical Dictionary
- David Gardner, Dolores Shoback. Basic And Clinical Endocrinology. McGraw-Hill Medical; 2011. 9th Edition. Pg. 550
- Dickerman, R. D.; Stevens, Q. E.; Steide, J. A.; Schneider, S. J. (2004). "Precocious puberty associated with a pineal cyst: is it disinhibition of the hypothalamic-pituitary axis?". Neuro endocrinology letters 25 (3): 173–175. PMID 15349080.
- "Little Mother". Time. 1957-12-16. Archived from the original on 2009-07-16. Retrieved 2008-01-09.
- Snopes.com (21 Jul 2004). "Youngest Mother". Retrieved January 16, 2009.
- Yamato, Fumiko; Takaya, Junji; Higashino, Hirohiko; Yamanouchi, Yasuo; Suehara, Hiroshi; Kobayashi, Yohnosuke (March 2005). "Slipped capital femoral epiphysis during the treatment of precocious puberty with a gonadotropin-releasing hormone-agonist: aetiological considerations". European Journal of Pediatrics 164 (3): 173–174. doi:10.1007/s00431-004-1578-7. PMID 15592875.
- Masse, R. J.; Shaw, P. J.; Burgess, M. (2008). "Intracranial choriocarcinoma causing precocious puberty and cured with combined modality therapy". Journal of Paediatrics and Child Health 29 (6): 464–467. doi:10.1111/j.1440-1754.1993.tb03022.x. PMID 8286166.
- Antoniazzi, F.; Zamboni, G. (2004). "Central precocious puberty: current treatment options". Paediatric drugs 6 (4): 211–231. doi:10.2165/00148581-200406040-00002. PMID 15339200.)
- (Tanner, 1990).
- Kaplowitz, P. B.; Slora, E. J.; Wasserman, R. C.; Pedlow, S. E.; Herman-Giddens, M. E. (2001). "Earlier onset of puberty in girls: relation to increased body mass index and race". Pediatrics 108 (2): 347–353. doi:10.1542/peds.108.2.347. PMID 11483799.
- McKenna, Phil (2007-03-05). "Childhood obesity brings early puberty for girls". New Scientist. Archived from the original on 2008-04-19. Retrieved 2010-05-22.
- Jane Houlihan, Sonya Lunder, Anila Jacob. "Timeline: BPA from Invention to Phase-Out". Environmental Working Group.
- Libertun, C.; Lux-Lantos, V.; Bianchi, M.; Fernández, M. (2009). "Neonatal Exposure to Bisphenol a Alters Reproductive Parameters and Gonadotropin Releasing Hormone Signaling in Female Rats". Environmental Health Perspectives. doi:10.1289/ehp.0800267.
- Cooney, Elizabeth (2010-02-11). "Puberty gap: Obesity splits boys, girls. Adolescent males at top of the BMI chart may be delayed". MSNBC. Retrieved 2010-05-22.
- "Childhood Obesity May Contribute to Later Onset of Puberty for Boys". Science Daily. February 2010. Retrieved 2010-05-22.
- Kuo, H. C.; Sheen, J. M.; Wu, K. S.; Wei, H. H.; Hsiao, C. C. (2006). "Precocious puberty due to human chorionic gonadotropin-secreting pineal tumor". Chang Gung medical journal 29 (2): 198–202. PMID 16767969.
- Esouifino, A. I.; Villanúa, M. A.; Agrasal, C. (1987). "Effect of neonatal melatonin administration on sexual development in the rat". Journal of Steroid Biochemistry 27 (4–6): 1089–1093. doi:10.1016/0022-4731(87)90194-4. PMID 3121932.
- Park, Sung Won; Lee, Seung-Tae; Sohn, Young Bae; Cho, Sung Yoon; Kim, Se-Hwa; Kim, Su Jin; Kim, Chi Hwa; Ko, Ah-Ra; Paik, Kyung-Hoon; Kim, Jong-Won; Jin, Dong-Kyu (1 January 2012). "polymorphisms are associated with central precocious puberty and early puberty in girls". Korean Journal of Pediatrics 55 (10): 388–92. doi:10.3345/kjp.2012.55.10.388. PMC 3488615. PMID 23133486.
- Ong, Ken K; Elks, Cathy E; Li, Shengxu; Zhao, Jing Hua; Luan, Jian'an; Andersen, Lars B; Bingham, Sheila A; Brage, Soren; Smith, George Davey; Ekelund, Ulf; Gillson, Christopher J; Glaser, Beate; Golding, Jean; Hardy, Rebecca; Khaw, Kay-Tee; Kuh, Diana; Luben, Robert; Marcus, Michele; McGeehin, Michael A; Ness, Andrew R; Northstone, Kate; Ring, Susan M; Rubin, Carol; Sims, Matthew A; Song, Kijoung; Strachan, David P; Vollenweider, Peter; Waeber, Gerard; Waterworth, Dawn M; Wong, Andrew; Deloukas, Panagiotis; Barroso, Inês; Mooser, Vincent; Loos, Ruth J; Wareham, Nicholas J (16 May 2009). "Genetic variation in LIN28B is associated with the timing of puberty". Nature Genetics 41 (6): 729–733. doi:10.1038/ng.382. PMC 3000552. PMID 19448623.
- Su, Pen-Hua; Yang, Shun-Fa; Yu, Ju-Shan; Chen, Suh-Jen; Chen, Jia-Yuh (15 February 2012). "Study of leptin levels and gene polymorphisms in patients with central precocious puberty". Pediatric Research 71 (4–1): 361–367. doi:10.1038/pr.2011.69. PMID 22391636.
- Zhu H, Shah S, Shyh-Chang N, Shinoda G, Einhorn WS, Viswanathan SR, Takeuchi A, Grasemann C, Rinn JL, Lopez MF, Hirschhorn JN, Palmert MR, Daley GQ. (July 2010). "Lin28a transgenic mice manifest size and puberty phenotypes identified in human genetic association studies". Nat Genet 42 (7): 626–30. doi:10.1038/ng.593. PMC 3069638. PMID 20512147.
- Teles, Milena Gurgel; Silveira, Leticia Ferreira Gontijo; Tusset, Cintia; Latronico, Ana Claudia (1 October 2011). "New genetic factors implicated in human GnRH-dependent precocious puberty: The role of kisspeptin system". Molecular and Cellular Endocrinology 346 (1–2): 84–90. doi:10.1016/j.mce.2011.05.019. PMID 21664234.
- Silveira, LG; Noel, SD; Silveira-Neto, AP; Abreu, AP; Brito, VN; Santos, MG; Bianco, SD; Kuohung, W; Xu, S; Gryngarten, M; Escobar, ME; Arnhold, IJ; Mendonca, BB; Kaiser, UB; Latronico, AC (May 2010). "Mutations of the KISS1 gene in disorders of puberty". The Journal of Clinical Endocrinology and Metabolism 95 (5): 2276–80. doi:10.1210/jc.2009-2421. PMC 2869552. PMID 20237166.
- Tommiska, Johanna; Sørensen, Kaspar; Aksglaede, Lise; Koivu, Rosanna; Puhakka, Lea; Juul, Anders; Raivio, Taneli (1 January 2011). "LIN28B, LIN28A, KISS1, and KISS1R in idiopathic central precocious puberty". BMC Research Notes 4 (1): 363. doi:10.1186/1756-0500-4-363. PMC 3184284. PMID 21939553.
- (Stattin & Magnussion, 1990).
- Mendle J, Leve L, Van Ryzin M, Natsuaki M. (August 2013). "Linking Childhood Maltreatment With Girls' Internalizing Symptoms: Early Puberty as a Tipping Point". Journal of Research on Adolescence 24 (3): 626–30. doi:10.1111/jora.12075.
- (Caspi et al.1993: Lanza and Collins, 2002)
- Garn, SM. Physical growth and development. In: Friedman SB, Fisher M, Schonberg SK. , editors. Comprehensive Adolescent Health Care. St Louis: Quality Medical Publishing; 1992. Retrieved on 2009-02-20
- Susman, EJ; Dorn, LD; Schiefelbein, VL. Puberty, sexuality, and health. In: Lerner MA, Easterbrooks MA, Mistry J. , editors. Comprehensive Handbook of Psychology. New York: Wiley; 2003. Retrieved on 2009-02-20
- Zukauskaite, S.; Lasiene, D.; Lasas, L.; Urbonaite, B.; Hindmarsh, P. (2005). "Onset of breast and pubic hair development in 1231 preadolescent Lithuanian schoolgirls". Archives of Disease in Childhood 90 (9): 932–936. doi:10.1136/adc.2004.057612. PMC 1720558. PMID 15855182.
- Roberts, Michelle (2005-05-15). "Why puberty now begins at seven". BBC News. Retrieved 2010-05-22.
- Ritter, Jim (2000-08-02). "Parents worried by girls' earlier start of puberty". Chicago Sun-Times.
- Diana Zuckerman Ph.D. (2001). "Early Puberty in Girls". The Ribbon. Cornell University Program on Breast Cancer and Environmental Risk Factors. Retrieved 14 January 2010.
- Florence Comite; Cutler, Gordon B.; Rivier, Jean; Vale, Wylie W.; Loriaux, D. Lynn; Crowley, William F. (24 December 1981). "Short-Term Treatment of Idiopathic Precocious Puberty with a Long-Acting Analogue of Luteinizing Hormone-Releasing Hormone". New England Journal of Medicine 305 (26): 1546–1550. doi:10.1056/NEJM198112243052602. PMID 6458765.
- Your Child - Puberty by University of Michigan
- PSM by Child Growth Foundation
- Central Precocious Puberty