In Silico Structural and Biochemical Functional Analysis of a Novel CYP21A2 Pathogenic Variant.

Cohen, Michal; Pignatti, Emanuele; Dines, Monica; Mory, Adi; Ekhilevitch, Nina; Kolodny, Rachel; Flück, Christa E.; Tiosano, Dov (2020). In Silico Structural and Biochemical Functional Analysis of a Novel CYP21A2 Pathogenic Variant. International journal of molecular sciences, 21(16) MDPI 10.3390/ijms21165857

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Classical congenital adrenal hyperplasia (CAH) caused by pathogenic variants in the steroid 21-hydroxylase gene (CYP21A2) is a severe life-threatening condition. We present a detailed investigation of the molecular and functional characteristics of a novel pathogenic variant in this gene. The patient, 46 XX newborn, was diagnosed with classical salt wasting CAH in the neonatal period after initially presenting with ambiguous genitalia. Multiplex ligation-dependent probe analysis demonstrated a full deletion of the paternal CYP21A2 gene, and Sanger sequencing revealed a novel de novo CYP21A2 variant c.694-696del (E232del) in the other allele. This variant resulted in the deletion of a non-conserved single amino acid, and its functional relevance was initially undetermined. We used both in silico and in vitro methods to determine the mechanistic significance of this mutation. Computational analysis relied on the solved structure of the protein (Protein-data-bank ID 4Y8W), structure prediction of the mutated protein, evolutionary analysis, and manual inspection. We predicted impaired stability and functionality of the protein due to a rotatory disposition of amino acids in positions downstream of the deletion. In vitro biochemical evaluation of enzymatic activity supported these predictions, demonstrating reduced protein levels to 22% compared to the wild-type form and decreased hydroxylase activity to 1-4%. This case demonstrates the potential of combining in-silico analysis based on evolutionary information and structure prediction with biochemical studies. This approach can be used to investigate other genetic variants to understand their potential effects.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > Unit Childrens Hospital > Forschungsgruppe Endokrinologie / Diabetologie / Metabolik (Pädiatrie)
04 Faculty of Medicine > Department of Gynaecology, Paediatrics and Endocrinology (DFKE) > Clinic of Paediatric Medicine
04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR)
04 Faculty of Medicine > Department of Gynaecology, Paediatrics and Endocrinology (DFKE) > Clinic of Paediatric Medicine > Endocrinology/Metabolic Disorders

UniBE Contributor:

Pignatti, Emanuele and Flück Pandey, Christa Emma

Subjects:

600 Technology > 610 Medicine & health
500 Science > 570 Life sciences; biology

ISSN:

1422-0067

Publisher:

MDPI

Language:

English

Submitter:

Christa Emma Flück Pandey

Date Deposited:

28 Dec 2020 18:27

Last Modified:

28 Dec 2020 18:35

Publisher DOI:

10.3390/ijms21165857

PubMed ID:

32824094

Uncontrolled Keywords:

CYP21A2 VUS congenital adrenal hyperplasia consurf in silico protein structure

BORIS DOI:

10.48350/150411

URI:

https://boris.unibe.ch/id/eprint/150411

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