LRP5 high bone mass (Worth-type autosomal dominant endosteal hyperostosis): case report and historical review of the literature

Purpose: LRP5 high bone mass (HBM) is an autosomal dominant endosteal hyperostosis caused by mutations of the low-density lipoprotein receptor-related protein 5 (LRP5) gene. Alternative names included "autosomal dominant osteosclerosis" and "Worth disease." The aim of the paper is to provide an historical overview of a disorder whose literature is complicated and confusing due to the past use of several denominations and lack of reviews.

Methods: We collected case reports of HBM with evidence of autosomal dominant transmission preceding the identification of the LRP5 mutations in 2002 (Worth-type endosteal hyperostosis) and cases of LRP5 HBM confirmed by genetic analysis since 2002. The prevalence of relevant clinical and laboratory findings was estimated. We described an affected woman with neurological manifestations.

Results: A 44-year-old Caucasian woman with torus palatinus complained of headache, hypo-/anosmia, and complete mixed deafness. Dual-energy X-ray absorptiometry (DEXA) scan revealed elevated bone mass. The A242T mutation of the LRP5 gene was detected. Including the present case, 155 patients have been reported to date. Neurological involvement and increased serum alkaline phosphatase (ALP) were present in 19.4% and 3.7% of cases, respectively. Facial changes and torus palatinus were observed in 61% and 41% of cases, respectively.

Conclusions: We present the only historical review on Worth-type endosteal hyperostosis, now known as LRP5 HBM. Neurological manifestations, previously considered absent in the disease, affect 19.4% of the patients. Genetic analysis and appropriate denomination of LRP5 HBM are fundamental for diagnosis and to mitigate the confusion that has long characterized this disease.