{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nThe Deleted in Azoospermia (DAZ) gene family, located in the AZFc region of the Y chromosome, is essential for normal human spermatogenesis. Among its four copies, DAZ2 is expressed in the testes and contributes to proper germ cell development, as demonstrated by analyses showing active expression in human testicular tissue."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nMultiple genetic studies have revealed that deletions affecting the DAZ2 copy—often occurring as part of a combined DAZ1/DAZ2 deletion—correlate with impaired spermatogenesis and male infertility. In East Asian and Chinese populations, analyses have documented that deletion of the DAZ1/DAZ2 unit is a predominant subtype of partial AZFc deletion associated with significant spermatogenic damage. Further, targeted screening using PCR‐restriction fragment length polymorphism and meta-analysis approaches consistently show that partial deletion of the DAZ1/DAZ2 copies is a high‐risk factor for severe oligozoospermia and azoospermia. In addition, studies in diverse cohorts—including South Chinese and Tunisian populations—have identified novel deletion patterns (such as a gr/gr-DAZ2-DAZ4-CDY1b deletion) where removal of the DAZ2 copy appears to contribute to spermatogenic failure."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "2", "end_ref": "8"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nEmerging functional studies have also implicated DAZ2 in cell fate reprogramming. Overexpression of DAZ2, together with other germ cell factors such as DAZL and BOULE, can reprogram human Sertoli cells into spermatogonial stem cells with the ability to self‐renew and differentiate into mature germ cells. This finding opens new avenues for potential therapeutic strategies in treating male infertility by generating gametes from somatic cells."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "9"}]}, {"type": "t", "text": ""}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Byunghyuk Kim, Youngbin Lee, Yeonwha Kim, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Polymorphic expression of DAZ proteins in the human testis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Hum Reprod (2009)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1093/humrep/dep032"}], "href": "https://doi.org/10.1093/humrep/dep032"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19223287"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19223287"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "F Zhang, Z Li, B Wen, et al. "}, {"type": "b", "children": [{"type": "t", "text": "A frequent partial AZFc deletion does not render an increased risk of spermatogenic impairment in East Asians."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Ann Hum Genet (2006)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1111/j.1529-8817.2005.00231.x"}], "href": "https://doi.org/10.1111/j.1529-8817.2005.00231.x"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "16674553"}], "href": "https://pubmed.ncbi.nlm.nih.gov/16674553"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "A Ferlin, E Moro, A Rossi, et al. 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