Обсуждение:Врождённая гиперплазия коры надпочечников вследствие недостаточности 21-гидроксилазы

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Тандемные повторы, псевдоген, рекомбинация, en:Gene conversion и т.п. Отсюда. Цитата:

The 21-OH gene (CYP21) is located on chromosome 6p21.3 within the human leukocyte antigen (HLA) histocompatibility complex, together with a highly homologous inactive pseudogene (CYP21P). The two genes are located in tandem repeats, with the genes encoding the fourth component of serum complement (C4A and C4B). CYP21 and CYP21P genes consist of 10 exons and show a high homology with a nucleotide identity of 98% in their exon and 96% in their intron sequences (1, 2). Most mutations causing 21-OH deficiency arise from recombinations between CYP21 and CYP21P: when deleterious sequences normally present in the pseudogene are transferred to the active gene, the latter becomes incapable of encoding a normal enzyme. This process, called gene conversion, represents approximately 75% of the deleterious mutations. About 20% are meiotic recombinations that delete a 30-kb gene segment that encompasses the 3' end of the CYP21P, all of the adjacent C4B gene, and the 5' end of the CYP21, producing a nonfunctional chimeric pseudogene (2). The remaining 5% are de novo mutations that do not originate from the pseudogene, and they are unique within single families.

-нужно разобраться и разместить как можно более понятное объяснение в статье. --CopperKettle 20:24, 14 ноября 2009 (UTC)