Low-density lipoprotein receptor-related protein 5(LRP-5) is also known as BMND1, EVR1, EVR4, HBM, LR3, LRP7, OPPG, OPTA1, VBCH2, LDL receptor related protein 5 and PCLD4. LRP5 is a transmembrane low-density lipoprotein receptor that shares a similar structure with LRP6. LRP5 acts as a co-receptor with LRP6 and the Frizzled protein family members for transducing signals by Wnt proteins through the canonical Wnt pathway. This protein plays a key role in skeletal homeostasis. Mutations in LRP5 can lead to considerable changes in bone mass. A loss-of-function mutation causes osteoporosis-pseudoglioma (decrease in bone mass), while a gain-of-function mutation causes drastic increases in bone mass.