تسجيل الدخول

تسجيل

Molecular Genetic testing for CYP21A2 Gene Mutations

المؤلف:  Wass, J. A. H., Arlt, W., & Semple, R. K. (Eds.).

المصدر:  Oxford Textbook of Endocrinology and Diabetes

الجزء والصفحة:  3rd edition , p936

2026-08-16

44

 Southern blot analysis has been the gold standard for the detection of CYP21A2 gene deletions and CYP21A1P/ CYP21A2 chimeric genes. However, Southern Blot analysis requires relatively large amounts of high- quality DNA, is labour intensive and time consuming. In addition, CYP21A1P duplications and certain rare rearrangements at this locus may impede the detection of CYP21A2 gene deletions or duplications. Several approaches for gene dosage detection have been developed to overcome the disadvantages of Southern Blot analysis. The most widely used approach in current practice is multiplex ligation- dependent probe amplification (MLPA). MPLA requires only small amounts of DNA for detection of gene deletions, rearrangements and fusion genes.

The design of CYP21A2- specific primers for PCR- based amplification of CYP21A is crucial to avoid amplification of the pseudo gene and allele dropout by non- amplifying PCR fragments. This is challenging due to the high number of polymorphisms found across CYP21A2 and the high homology with its pseudogene. A variety of targeted molecular genetic strategies for detecting mutations have been published. Direct sequencing of the amplified PCR products combined with a method for the detection of gene deletions and chimeric genes are the only available strategies that allow for the detection of 100% of CYP21A2 mutated alleles and due to decreasing costs represents the method of choice in most routine laboratories.