Functional analyses of novel nucleotides variations in the CYP21A2 gene identified in patients with congenital adrenal hyperplasia

Abstract

Congenital Adrenal Hyperplasia (CAH), one of the most frequent autosome recessive disorders, is caused by defects in steroidogenic enzymes involved in the cortisol biosynthesis. One consequence of this is the deviation to the synthesis of androgenic hormones. Intrauterine prenatal exposure to androgen excess in critical stages of sexual differentiation leads to external genitalia virilization of 46,XX fetus and can result in ambiguous genitalia at birth.Screening of CAH affected families in our research group identified novel mutations. To continue this study, the objective of this project is to analyze the functional role of five such mutations (p.Leu12Met; p.Arg16Cys; p.Asp377Tyr; p.Thr450Met; p.Leu461Pro), one novel in frame deletion (p.(Gln398_Ala391del)), one known mutation without in vitro studies (p.Ser202Gly) and one combination of novel mutations (p.Asp377Tyr+p.Leu461Pro) in CYP21A2 protein. The methodology for this study will include: expression of normal and mutants CYP21A2 gene, enzymatic activity assay, protein kinetics and Western blotting.Those techniques will be performed in the department of Molecular Medicine and Surgery at the Karolinska Institute, in Sweden. The responsible for the Inborn Errors of Endocrinology and Metabolism Group is Dr. Anna Wedell and the pediatrician/molecular biologist is Dr. Svetlana Lajic, who also develop research with CYP21A2 gene in patients with CAH and is part of one of the most respected researches group in the CAH studies in Europe. (AU)