[Characterization of steroid 21-hydroxylase gene mutations in a oligosymptomatic form of congenital adrenal hyperplasia: family study].

Abstract

BACKGROUND:

21-hydroxilase deficiency accounts for over 90% of all cases of congenital adrenal hyperplasia (CAH). There is a non-negligible incidence of both severe and nonclassical forms of this genetic disorder. Enzyme deficiency is due to mutations in the gene encoding adrenal 21-hydroxylase (named CYP 21B) and is inherited in an autosomical recesive way. Complete or partial impairment of enzyme activity has been correlated with the different clinical forms of the disease.

PATIENTS AND METHODS:

In the present paper CYP 21B gene analysis results obtained in a family with two kindred affected by a nonclassical form of the disease are shown. Clinical assessment of these two kindred showed a very mild form of the disease, whereas biochemical results suggested a late-onset partial 21-hydroxylase deficiency. Genotyping for deletions and 10 point mutations in the CYP 21B gene was performed by Southern blot analysis and polymerase chain reaction (PCR) allele-specific oligonucleotide (ASO) hybridation technique.

RESULTS:

Molecular genetic analysis performed in the two affected patients and two further relatives allowed us to detect the presence of different mutations in the two alleles of the CYP 21B gene. One of these mutations was severe (655G) and came from maternal line, whereas the other was mild (Val281Leu) and originated in paternal line.

CONCLUSION:

Molecular genetic analysis allows the possibility of finding severe (and non-expected) mutations in patients with clinically mild and late-onset forms of the 21-hydroxylase deficiency.

• Authors: M A Martínez Olmos, J M Varela, B Ezquieta, N Hillman, J J Díez
• Journal: Medicina clinica (Med Clin (Barc)) Vol. 109 Issue 11 Pg. 421-4 (Oct 04 1997) ISSN: 0025-7753 [Print] Spain
• Vernacular Title: Caracterización de las mutaciones del gen de la esteroide 21-hidroxilasa en una forma oligosintomática de hiperplasia suprarrenal congénita: estudio familiar.
• PMID: 9379733 (Publication Type: Case Reports, Journal Article)

Chemical References

• Steroid 21-Hydroxylase

Topics

• Adolescent
• Adrenal Hyperplasia, Congenital (enzymology, genetics)
• Adult
• Alleles
• Child
• DNA Mutational Analysis
• Female
• Genotype
• Humans
• Male
• Mutation
• Pedigree
• Steroid 21-Hydroxylase (genetics)