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Sexual development before the age of eight in girls, and age 10 in boys.
Not every child reaches puberty at the same time, but in most cases it's safe to predict that sexual development will begin at about age 11 in girls and 12 or 13 in boys. However, occasionally a child begins to develop sexually much earlier. Between four to eight times more common in girls than boys, precocious puberty occurs in one out of every 5,000 to 10,000 U.S. children.
Precocious puberty often begins before age 8 in girls, triggering the development of breasts and hair under the arms and in the genital region. The onset of ovulation and menstruation also may occur. In boys, the condition triggers the development of a large penis and testicles, with spontaneous erections and the production of sperm. Hair grows on the face, under arms and in the pubic area, and acne may become a problem.
While the early onset of puberty may seem fairly benign, in fact it can cause problems when hormones trigger changes in the growth pattern, essentially halting growth before the child has reached normal adult height. Girls may never grow above 5 ft (152 cm) and boys often stop growing by about 5 ft 2 in (157 cm).
The abnormal growth patterns are not the only problem, however. Children with this condition look noticeably different than their peers, and may feel rejected by their friends and socially isolated. Adults may expect these children to act more maturely simply because they look so much older. As a result, many of these children-especially boys-are much more aggressive than others their own age, leading to behavior problems both at home and at school.
Causes and symptoms
Puberty begins when the brain secretes a hormone that triggers the pituitary gland to release gonadotropins, which in turn stimulate the ovaries or testes to produce sex hormones. These sex hormones (especially estrogen in girls and testosterone in boys) are what causes the onset of sexual maturity.
The hormonal changes of precious puberty are normal-it's just that the whole process begins a few years too soon. Especially in girls, there is not usually any underlying problem that causes the process to begin too soon. However, some boys do inherit the condition; the responsible gene may be passed directly from father to son, or inherited indirectly from the maternal grandfather through the mother, who does not begin early puberty herself. This genetic condition in girls can be traced in only about 1% of cases.
In about 15% of cases, there is an underlying cause for the precocious puberty, and it is important to search for these causes. The condition may result from a benign tumor in the part of the brain that releases hormones. Less commonly, it may be caused by other types of brain tumors, central nervous system disorders, or adrenal gland problems.
Physical exams can reveal the development of sexual characteristics in a young child. Bone x rays can reveal bone age, and pelvic ultrasound may show an enlarged uterus and rule out ovarian or adrenal tumors. Blood tests can highlight higher-than-normal levels of hormones. MRI or CAT scans should be considered to rule out intracranial tumors.
Treatment aims to halt or reverse sexual development so as to stop the accompanying rapid growth that will limit a child's height. There are two possible approaches: either treat the underlying condition (such as an ovarian or intracranial tumor) or change the hormonal balance to stop sexual development. It may not be possible to treat the underlying condition; for this reason, treatment is usually aimed at adjusting hormone levels.
There are several drugs that have been developed to do this:
- histrelin (Supprelin)
- nafarelin (Synarel)
- synthetic gonadotropin-releasing hormone agonist
Drug treatments can slow growth to 2-3 in (5-7.5 cm) a year, allowing these children to reach normal adult height, although the long-term effects aren't known.
National Institute of Child Health and Human Development. Bldg 31, Room 2A32, MSC 2425, 31 Center Drive, Bethesda, MD 20892-2425. (800) 505-2742. http://www.nichd.nih.gov/sids/sids.htm.
the period during which the secondary sex characters begin to develop and the capability of sexual reproduction is attained. In girls it is marked by broadening of the hips, development of the breasts, appearance of pubic hair, and onset of menstruation. In boys it is marked by broadening of the shoulders, deepening of the voice, and appearance of pubic and facial hair. Girls usually reach puberty between age 11 and 13, and boys between 13 and 15, although the timing varies widely.
precocious puberty unusually early sexual maturation, defined as before age 8 in girls and 9 in boys; both isosexual and contrasexual types occur. It is usually hormonal (central or true precocious p.,) although occasionally it occurs in otherwise normal children, such as those with a family history of it (constitutional precocious p.).
condition in which pubertal changes begin at an unexpectedly early age. This can involve the initiation of the normal hypothalamopituitary axis changes before the age of 8 in girls, and age 9 in boys. Idiopathic causes are most common.
A condition in which the changes associated with puberty begin at an unexpectedly early age, often caused by a pathological process involving a glandular secretion of estrogens or androgens.
Etymology: L, praecoquere, to mature early, pubertas
abnormally early development of sexual maturity. It is usually marked by early breast development and ovulation in girls before 8 years of age and the production of mature sperm in boys before 10 years of age.
precocious pubertyPremature puberty, pubertas precox Endocrinology The appearance of 2º sexual characteristics < age 8 in ♀–complete by age 9; < age 9 in ♂–complete by age 11; if caused by hypothalamic-pituitary axis activation, it is known as complete or true PP; if the precocity is 2º
to ectopic production or autonomous secretion of end-organ hormones,
it is designated incomplete PP. See Premature puberty, Pseudoprecocity. Cf Pubertal delay.
True or complete precocious puberty–affects both sexes
Constitutional or familial
CNS disease, eg tumors (hypothalamic and pineal gliomas, craniopharyngiomas, germinomas, hamartomas of the tuber cinereum), encephalitis, abscesses, cysts, sarcoidosis, TB
Virilizing syndromes, eg congenital adrenal hyperplasia
Incomplete or partial precocious puberty
♂Due to gonadotropin-secreting tumors, eg hepatoma, Leydig cell tumor, excessive androgen production or premature Leydig cell and germ cell maturation
♀Due to ovarian follicle cysts or estrogen-producing neoplasms, eg granulosa cell tumor
pre·co·cious pu·ber·ty(prē-kō'shŭs pyū'bĕr-tē)
Condition in which pubertal changes begin at an unexpectedly early age.
precocious pubertyThe onset of physical sexual maturity at an abnormally early age, arbitrarily set at prior to 6 years for girls and 7 years for boys. If there are signs of unusually rapid development of the secondary sexual characteristics or growth before 8 in girls or 9 in boys, precocious puberty should be suspected.
pre·co·cious pu·ber·ty(prē-kō'shŭs pyū'bĕr-tē) [MIM*176400]
Condition in which pubertal changes begin unexpectedly early.