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Androgen insensitivity syndrome classification

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aravind Reddy Kothagadi M.B.B.S[2]

Overview

Androgen insensitivity syndrome (AIS) represents a spectrum of defects in androgen action and can be subdivided into three broad phenotypes into complete androgen insensitivity syndrome (CAIS), mild androgen insensitivity syndrome (MAIS) and partial androgen insensitivity syndrome (PAIS).

Classification

  • Based on the degree of genital masculinization, androgen insensitivity syndrome is divided into three categories:[1][2][3][4]
  • When the external genitalia is that of a normal female it is classified as complete androgen insensitivity syndrome (CAIS)
  • When the external genitalia is that of a normal male it is classified as mild androgen insensitivity syndrome (MAIS)
  • When the external genitalia is partially, but not fully masculinized it is classified as partial androgen insensitivity syndrome (PAIS)
  • Individuals with both partial androgen insensitivity syndrome (PAIS) and complete androgen insensitivity syndrome (CAIS) have 46 XY karyotypes. [1]

Classification of Androgen Insensitivity Syndrome Phenotypes:’ [5]

Classification of Androgen Insensitivity Syndrome Phenotypes
Type External Genitalia Findings
CAIS – (Complete androgen insensitivity syndrome) Female (“testicular feminization”)
  • Absent OR rudimentary wolffian duct derivatives.
  • Absence or presence of epididymides and/or vas deferens.
  • Inguinal, labial, or abdominal testes.
  • Short blind-ending vagina.
  • Scant OR absent pubic AND/OR axillary hair.
Predominantly female (“incomplete AIS”)
  • Inguinal OR labial testes.
  • Clitoromegaly and labial fusion.
  • Distinct urethral and vaginal openings OR a urogenital sinus.
PAIS – (Partial androgen insensitivity syndrome) Ambiguous
  • Microphallus (<1 cm) with clitoris-like underdeveloped glans; labia majora-like bifid scrotum.
  • Descended OR undescended testes.
  • Perineoscrotal hypospadias OR urogenital sinus.
  • Gynecomastia (development of breasts) in puberty.
Predominantly male
  • Simple (glandular or penile) OR severe (perineal) “isolated” hypospadias with a normal-sized penis and descended testes OR severe hypospadias with micropenis, bifid scrotum, and either descended OR undescended testes.
  • Gynecomastia in puberty.
MAIS – (Mild androgen insensitivity syndrome) Male (“undervirilized male syndrome”)
  • Impaired spermatogenesis AND/OR impaired pubertal virilization.
  • Gynecomastia in puberty.

References

  1. 1.0 1.1 Bhaskararao G, Himabindu Y, Nayak SR, Sriharibabu M (2014). “Laparoscopic gonedectomy in a case of complete androgen insensitivity syndrome”. J Hum Reprod Sci. 7 (3): 221–3. doi:10.4103/0974-1208.142498. PMC 4229800. PMID 25395750.
  2. Ohba K, Hayashida Y, Hakariya H, Ichinose S, Naitou S (2009). “[Case of complete androgen insensitivity syndrome]”. Hinyokika Kiyo (in Japanese). 55 (5): 277–80. PMID 19507547.
  3. Oakes MB, Eyvazzadeh AD, Quint E, Smith YR (2008). “Complete androgen insensitivity syndrome–a review”. J Pediatr Adolesc Gynecol. 21 (6): 305–10. doi:10.1016/j.jpag.2007.09.006. PMID 19064222.
  4. Hashmi A, Hanif F, Hanif SM, Abdullah FE, Shamim MS (2008). “Complete Androgen Insensitivity Syndrome”. J Coll Physicians Surg Pak. 18 (7): 442–4. doi:07.2008/JCPSP.442444 Check |doi= value (help). PMID 18760072.
  5. Pagon RA, Adam MP, Ardinger HH, Wallace SE, Amemiya A, Bean L, Bird TD, Ledbetter N, Mefford HC, Smith R, Stephens K, Gottlieb B, Trifiro MA. PMID 20301602. Vancouver style error: initials (help); Missing or empty |title= (help)

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