(Redirected from Virilisation)In biology and medicine, 'virilization' refers to the biological development of
sex differences, changes which make a
male body different from a
female body. Most of the changes of virilization are produced by
androgens. Virilization is most commonly used in three medical and
biology of gender contexts: prenatal
sexual differentiation, the postnatal changes of normal male
puberty, and excessive androgen effects in girls or women.
Prenatal virilization
In the prenatal period, virilization refers to closure of the
perineum, thinning and rugation of the
scrotum, growth of the
phallus, and closure of the
urethral groove to the tip of the
penis. In this context ''masculinization'' is synonymous with virilization. Prenatal virilization of genetic females and undervirilization of genetic males are common causes of
ambiguous genitalia and
intersex conditions.
''Undervirilization'' can occur if a genetic male cannot produce enough androgen or the body tissues cannot respond to it. Extreme undervirilization occurs when no significant androgen can be produced or the body is completely insensitive to it, and results in a female body. Partial undervirilization produces ambiguous genitalia part way between male and female. The mildest degree of undervirilization may be a slightly small penis with
hypospadias. Examples of undervirilization are
androgen insensitivity syndrome,
5 alpha reductase deficiency, and some forms of
congenital adrenal hyperplasia.
Prenatal virilization (or masculinization) of a genetically female fetus can occur when an excessive amount of androgen is produced by the fetal
adrenal glands or is present in maternal blood. In the severest form of
congenital adrenal hyperplasia complete masculinization of a genetically female fetus results in an apparently normal baby boy with no palpable
testes. More often, the virilization is partial and the genitalia are ambiguous.
Normal virilization
In common as well as medical usage, virilization often refers to the process of normal male
puberty, in which
testosterone changes a boy's body into a man's. These effects include growth of the penis and
testes, accelerated growth, development of
pubic hair and other androgenic hair of face, torso, and limbs, deepening of the voice, increased musculature, thickening of the jaw, prominence of the neck cartilage, and broadening of the shoulders.
Abnormal childhood virilization
Virilization can occur in childhood in either boys or girls due to excessive amounts of androgens. Typical effects of virilization in children are
pubic hair, accelerated growth and bone maturation, increased muscle strength,
acne, adult body odor, and sometimes growth of the penis. In a boy, virilization may signal
precocious puberty, while
congenital adrenal hyperplasia and androgen producing tumors (usually) of the
gonads or adrenals are occasional causes in both sexes.
virilization in adolescent or adult women
Virilization in a woman can manifest as
clitoral enlargement, increased muscle strength, acne,
hirsutism, frontal hair thinning, deepening of the voice, and
menstrual disruption due to
anovulation.
Some of the possible causes of virilization in women are:
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Polycystic ovary syndrome
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Androgen-producing tumors of the
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★ ovaries
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★ adrenal glands
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★ pituitary gland
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Hypothyroidism
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Anabolic steroid exposure
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Congenital adrenal hyperplasia due to 21-hydroxylase deficiency (late-onset)
See also
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Sexual differentiation
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Secondary sex characteristics
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Ambiguous genitalia
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Androgen
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Hirsutism