Back to Search Start Over

A Mosaic Variant in CTNNB1/β-catenin as a Novel Cause for Osteopathia Striata With Cranial Sclerosis.

Authors :
Huybrechts Y
Appelman-Dijkstra NM
Steenackers E
Van Beylen W
Mortier G
Hendrickx G
Van Hul W
Source :
The Journal of clinical endocrinology and metabolism [J Clin Endocrinol Metab] 2024 Jun 17; Vol. 109 (7), pp. 1891-1898.
Publication Year :
2024

Abstract

Context: Osteopathia striata with cranial sclerosis (OSCS) is a rare bone disorder with X-linked dominant inheritance, characterized by a generalized hyperostosis in the skull and long bones and typical metaphyseal striations in the long bones. So far, loss-of-function variants in AMER1 (also known as WTX or FAM123B), encoding the APC membrane recruitment protein 1 (AMER1), have been described as the only molecular cause for OSCS. AMER1 promotes the degradation of β-catenin via AXIN stabilization, acting as a negative regulator of the WNT/β-catenin signaling pathway, a central pathway in bone formation.<br />Objective: In this study, we describe a Dutch adult woman with an OSCS-like phenotype, namely, generalized high bone mass and characteristic metaphyseal striations, but no genetic variant affecting AMER1.<br />Results: Whole exome sequencing led to the identification of a mosaic missense variant (c.876A > C; p.Lys292Asn) in CTNNB1, coding for β-catenin. The variant disrupts an amino acid known to be crucial for interaction with AXIN, a key factor in the β-catenin destruction complex. Western blotting experiments demonstrate that the p.Lys292Asn variant does not significantly affect the β-catenin phosphorylation status, and hence stability in the cytoplasm. Additionally, luciferase reporter assays were performed to investigate the effect of p.Lys292Asn β-catenin on canonical WNT signaling. These studies indicate an average 70-fold increase in canonical WNT signaling activity by p.Lys292Asn β-catenin.<br />Conclusion: In conclusion, this study indicates that somatic variants in the CTNNB1 gene could explain the pathogenesis of unsolved cases of osteopathia striata.<br /> (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Details

Language :
English
ISSN :
1945-7197
Volume :
109
Issue :
7
Database :
MEDLINE
Journal :
The Journal of clinical endocrinology and metabolism
Publication Type :
Academic Journal
Accession number :
38173341
Full Text :
https://doi.org/10.1210/clinem/dgad757