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Updated: Oct 22, 2025

In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila
Published on: August 20, 2019
Heterozygous variant in WNT1 gene in two brothers with early onset osteoporosis
Christie G Turin1, Kyu Sang Joeng2, Staci Kallish3
1Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd., 4th floor, Philadelphia, PA 19104, USA.
Abstract:
Osteoporosis is a multifactorial disorder characterized by low bone mass and strength, leading to increased risk of fracture. The WNT pathway plays a critical role in bone remodeling by enhancing osteoblastic differentiation, which promotes bone formation, and inhibiting osteoclastic differentiation, decreasing bone resorption. Therefore, genetic alterations of this pathway will lead to impaired bone homeostasis and could contribute to varying response to treatment. We present the case of two brothers with early osteoporosis who were found to have a heterozygous variant of unknown significance in the WNT1 gene, c.1060_1061delCAinsG (p.H354Afs*39). This finding demonstrates that frameshift variants in WNT1 may also act in a dominant fashion leading to decreased bone mass.
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