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Androgen Insensitivity Syndrome - Androgen Insensitivity Syndrome Symptom, Cause, Treatment
Androgen insensitivity syndrome (AIS), formerly known as testicular feminization, is an X-linked recessive condition resulting in a failure of normal masculinization of the external genitalia in chromosomally male individuals.The androgen insensitivity syndrome (AIS) typically includes evidence of feminization of the external genitalia at birth, abnormal secondary sexual development in puberty, and infertility. Humans have twenty-three pairs of chromosomes. On fertilisation, the chromosomes combine to give a total of forty-six (twenty-three pairs). A female usually has an XX pair of sex chromosomes and a man an XY pair.
Symptoms of Androgen Insensitivity Syndrome
The nature of the resulting problem varies according to the structure and sensitivity of the abnormal receptor. Most of the forms of AIS involve variable degrees of undervirilization and/or infertility in XY persons of either sex. A woman with complete androgen insensitivity syndrome (CAIS) has a nearly normal female body despite a 46XY karyotype and testes , a condition termed testicular feminization in the past.
Causes of Androgen Insensitivity Syndrome
The usual presentation is during childhood with a girl who has bilateral inguinal hernias, often containing the testes some affected persons will have features that fall between the phenotypes described.
- Prenatal amniocentesis discovers male karyotype not matched by ultrasound or obvious female appearance at birth.
- A lump in the inguinal canal is discovered to be a testis.
- Abdominal surgery done for repair of inguinal hernia , appendicitis or other reason discovers testes or lack of uterus and ovaries. Even in the absence of a visible inguinal lump, perhaps 1% of girls operated on for inguinal hernia are found to have AIS.
- Karyotype performed for unrelated purposes is found to be XY.
- The girl or family seeks evaluation for delayed menarche (primary amenorrhea ).
- The woman seeks explanation for difficulty with sexual intercourse .
- The woman seeks explanation for infertility .
Treatment of Androgen Insensitivity Syndrome
AIS is not usually diagnosed at birth.Most cases of Androgen Insensitivity Syndromeare diagnosed in the following circumstances.
- Complete AIS (CAIS): completely female body except no uterus, fallopian tubes or ovaries; testes in the abdomen; minimal androgenic (pubic or axillary) hair at puberty.
- Partial or incomplete AIS (PAIS): female body, with slightly virilized genitalia; testes in the abdomen; sparse to normal androgenic hair.
- Reifenstein syndrome: obviously ambiguous genitalia; small testes may be in abdomen or scrotum; sparse to normal androgenic hair; gynecomastia at puberty.
- Infertile male syndrome: normal male body internally and externally; normal virilization and androgenic hair; reduced sperm production; reduced fertility.
- Undervirilized fertile male syndrome: male internal and external genitalia with small penis; testes in scrotum; normal androgenic hair; sperm count and fertility normal or reduced.
- X-linked spinal and bulbar muscular atrophy: normal or nearly normal male body and fertility; exaggerated adolescent gynecomastia; adult onset degenerative muscle disease.
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