Targeted Gene Sequencing in a Male Adult Diagnosed With X-Linked Osteoporosis Due to a Novel p.(Arg398Profs*2) PLS3 Variant.

Pathogenic loss-of-function variants in the plastin-3 gene (PLS3), encoding plastin-3 protein, are associated with early-onset X-linked osteoporosis. We present the case of a young adult male patient, with a history of multiple fragility fractures and blue sclerae, who was clinically diagnosed with osteogenesis imperfecta (OI) type 1 in childhood. He has been managed with intravenous bisphosphonate therapy, leading to an increase in bone density at the spine, stable bone density at the femoral neck, and a period free of fractures while on antiresorptive therapy. Two decades later, with a focus on reproductive family planning, a novel PLS3 variant was identified on genetic testing. This case report highlights an important role for genetic testing in patients with early-onset osteoporosis or a clinical diagnosis of OI. With the emergence of new targeted therapeutics and advanced reproductive options, such as preimplantation genetic testing, obtaining an accurate molecular diagnosis is key.