Mutation of IVS2-12A/C>G in combination with 707-714delGAGACTAC in the CYP21 gene is caused by deletion of the C4-CYP21 repeat module with steroid 21-hydroxylase deficiency

Hsien Hsiung Lee, Shwu Fen Chang, Fuu Jen Tsai, Li Ping Tsai, Ching Yu Lin

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15 Citations (Scopus)


More than 90% of the cases of congenital adrenal hyperplasia are caused by mutations of the CYP21 gene. Approximately 75% of the defective CYP21 genes are generated through intergenic recombination, termed apparent gene conversion, from the neighboring CYP21P pseudogene. Among them, mutation of the aberrant splicing donor site of IVS2 -12A/C>G at nucleotide (nt) 655 is believed to be a result derived from this mechanism and is the most prevalent case among all ethnic groups. However, mutation of 707-714delGAGACTAC rarely exists alone, although this locus is a distance of 53 nt away from IVS2 -12A/C>G. From the molecular characterization of the mutation of IVS2 - 12A/C>G combined with 707-714delGAGACTAC in patients with congenital adrenal hyperplasia, we found that it appeared to be in a 3.2- rather than a 3.7-kb fragment generated by Taq I digestion in a PCR product of the CYP21 gene. Interestingly, the 5′ end region of such a CYP21 haplotype had CYP21P-specific sequences. Our results indicate that the coexistence of these two mutations is caused by deletion of the CYP21P, XA, RP2, and C4B genes and intergenic recombination in the C4-CYP21 repeat module. Surprisingly, this kind of the haplotype of the mutated CYP21 gene has not been reported as a gene deletion.

Original languageEnglish
Pages (from-to)2726-2729
Number of pages4
JournalJournal of Clinical Endocrinology and Metabolism
Issue number6
Publication statusPublished - Jun 1 2003


ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology, Diabetes and Metabolism

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