Abstract.
Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. More than 90% of CAH cases 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. A chimeric CYP21P/CYP21 gene with its 5′ end corresponding to CYP21P and 3′ end corresponding to CYP21 has been identified. This type of gene is nonfunctional because it produces a truncated protein. We found two distinct chimeric genes in CAH patients. Both genes had a sequence with −300 nucleotides of the 5′ head as the CYP21P gene. The coding region consisted of a fusion molecule with the CYP21P gene in two different regions. One of the junctions was located in the chi-like sequence of GCTGGGC in the third intron and the other was in the minisatellite consensus TGGCAGGAGG of exon 5 of the CYP21P gene. In addition, analysis of restriction fragment length polymorphism for these two 3.3-kb chimeric molecules showed that these sequences arose as a consequence of unequal crossover between the CYP21P and CYP21 genes. It is plausible that both consensus sequences are responsible for the gene conversion of these two chimeric genes.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Additional information
Received: March 13, 2002 / Accepted: June 17, 2002
Rights and permissions
About this article
Cite this article
Lee, HH., Niu, DM., Lin, RW. et al. Structural analysis of the chimeric CYP21P/CYP21 gene in steroid 21-hydroxylase deficiency. J Hum Genet 47, 517–522 (2002). https://doi.org/10.1007/s100380200077
Published:
Issue Date:
DOI: https://doi.org/10.1007/s100380200077
This article is cited by
-
Novel deletion alleles carrying CYP21A1P/A2chimeric genes in Brazilian patients with 21-hydroxylase deficiency
BMC Medical Genetics (2010)
-
The chimeric CYP21P/CYP21 gene and 21-hydroxylase deficiency
Journal of Human Genetics (2004)