Efficacy of denosumab therapy for osteoporosis-pseudoglioma syndrome with osteoporosis: a case report

Osteoporosis-pseudoglioma (OPPG) syndrome is a very rare autosomal recessive disorder caused by mutations in the low-density lipoprotein receptor-related protein-5 (LRP5) gene. Treatment with bisphosphonates (BPs), particularly with pamidronate and risedronate, has been reported to have efficacy in this condition. However, there has been no consensus treatment strategy for OPPG. Moreover, there has been no report on the efficacy of denosumab in an OPPG patient to date. We enrolled an OPPG patient with osteoporosis treated by denosumab for a year. We report on a 19-year-old male patient with OPPG due to compound heterozygous mutations on the LRP5 gene (c.1145C > T,p.P382L and c.4600C > T,p.R1534*) who showed a good response after a 12-month period of denosumab therapy. Consequently, bone metabolism and bone mineral density were significantly improved after the treatment. In addition, no fracture or adverse effect was observed during the study period. Although BPs are considered to be administered in OPPG patients as a first-line therapy during early childhood, denosumab could be a good option to treat OPPG.