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Azoospermia factor

  (Redirected from AZF2)

Azoospermia factor (AZF) refers to one of several proteins or their genes, which are coded from the AZF region on the human male Y chromosome.[1] Deletions in this region are associated with inability to produce sperm.[2] Subregions within the AZF region are AZFa (sometimes AZF1), AZFb and AZFc (together referred to as AZF2). AZF is the term used by the HUGO Gene Nomenclature Committee.[3]

azoospermia factor 1
Alt. symbolsAZF
Other data
LocusChr. Y q11



The AZF1 (Azoospermia Factor 1) gene is likely located in the euchromatic part of the long arm in Yq11.23. AZF1 is 792kb long and just distal to the centromere of the Y chromosome.[4] AZF1 genes are involved in spermatogenesis in the testes.


Originally, the AZFb and AZFc genes were identified and thought to be separate regions. They were later found to be overlapping and are now referred to as AZF2.


AZFc is one of the most genetically dynamic regions in the human genome, possibly serving as counter against the genetic degeneracy associated with the lack of a partner chromosome during meiosis.[5] However, such strategy comes has the adverse effects that some rearrangements represent a risk factor or a de facto causative agent of spermatogenic disruption.[5]

A specific partial deletion of AZFc called gr/gr deletion is significantly associated with male infertility among Caucasians in Europe and the Western Pacific region.[6]

AZF mutationsEdit

Mutations or deletions in the AZF genes are associated with inability or lessened ability to create sperm. It may cause azoospermia (not having any measurable level of sperm in semen). Deletions in the USP9Y gene, which is located within AZF1, are usually but not always associated with inability to form sperm.

See alsoEdit

External linksEdit


  1. ^ Repping S, Skaletsky H, Lange J, Silber S, Van Der Veen F, Oates R, Page D, Rozen S (2002). "Recombination between palindromes P5 and P1 on the human Y chromosome causes massive deletions and spermatogenic failure". Am J Hum Genet. 71 (4): 906–22. doi:10.1086/342928. PMC 419997. PMID 12297986.
  2. ^ Ioulianos A, Sismani C, Fourouclas N, Patroclou T, Sergiou C, Patsalis P (2002). "A nation-based population screening for azoospermia factor deletions in Greek-Cypriot patients with severe spermatogenic failure and normal fertile controls, using a specific study and experimental design". Int J Androl. 25 (3): 153–8. doi:10.1046/j.1365-2605.2002.00340.x. PMID 12031043.
  3. ^ "Archived copy". Archived from the original on 2006-08-22. Retrieved 2006-09-04.CS1 maint: Archived copy as title (link)
  4. ^ Vogt P (2005). "AZF deletions and Y chromosomal haplogroups: history and update based on sequence". Hum Reprod Update. 11 (4): 319–36. doi:10.1093/humupd/dmi017. PMID 15890785.
  5. ^ a b Navarro-Costa P, Gonçalves J, Plancha CE (March 2010). "The AZFc region of the Y chromosome: at the crossroads between genetic diversity and male infertility". Hum Reprod Update. 16 (5): 525–542. doi:10.1093/humupd/dmq005. PMC 2918367. PMID 20304777.
  6. ^ Stouffs, K.; Lissens, W.; Tournaye, H.; Haentjens, P. (2010). "What about gr/gr deletions and male infertility? Systematic review and meta-analysis". Human Reproduction Update. 17 (2): 197–209. doi:10.1093/humupd/dmq046. PMID 20959348.