Mutational spectrum of the steroid 21-hydroxylase gene in Austria: identification of a novel missense mutation.
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Baumgartner-Parzer SM, Schulze E, Waldhausl W, Pauschenwein S, Rondot S, Nowotny P, Meyer K, Frisch H, Waldhauser F, Vierhapper H
Mutational spectrum of the steroid 21-hydroxylase gene in Austria: identification of a novel missense mutation.
J Clin Endocrinol Metab. 2001 Oct;86(10):4771-5.
- PubMed ID
- 11600539 [ View in PubMed]
- Abstract
This study attempted an analysis of the mutational spectrum of 21-hydroxylase deficiency in 79 unrelated Austrian patients with classical and nonclassical forms of congenital adrenal hyperplasia and their respective 112 family members. Apparent large gene deletions/conversions were present in 31% of the 158 unrelated congenital adrenal hyperplasia alleles, whereas the most frequent point mutations were intron 2 splice (22.8%), I172N (15.8%), V281L (12%), and P30L (7.6%), in line with the frequencies reported for other countries. In 5 of the 12 congenital adrenal hyperplasia alleles carrying a P30L mutation the aberration is based on a single base substitution, whereas the remaining 7 represent part of a CYP21B conversion (1 allele) or CYP21B/21A hybrid gene (6 alleles), the latter characterized by a junction site before intron 2 as indicated by Southern blot, PCR, and sequence analyses. Previously described mutations were not present in 1.2% of unrelated congenital adrenal hyperplasia alleles, including one female patient presenting with severe genital virilization. Sequence analysis of the complete functional 21-hydroxylase gene revealed an as yet undescribed mutation in exon 10-Arg(426)His, which has not yet been described to represent a common pseudogene sequence. In vitro expression experiments showed the Arg(426)His mutant to exhibit only low enzyme activity toward the natural substrate 17-hydroxyprogesterone corresponding to the degree of disease manifestation in the patient in whom it was found.