Receptor tyrosine kinase-like orphan receptor 2, also known as ROR2, is a member of the Tyr protein kinase family and ROR subfamily of cell surface receptors. Located in the transmembrane, ROR2 is highly expressed during early embryonic development and is associated with chondrocyte formation, cartilage and growth plate maturity. Expression levels of ROR2 subside after 16 days and occur minimally in adults. ROR2 is post translationaly modified by ATM or ATR phosphorylation when DNA damage occurs. Mutations in ROR2 result in brachydactyly type B1 (BDB1), characterized by either hypoplasia or aplasia of the distal phalanges and nails. ROR2 is also associated with recessive Robinow syndrome (RRS), resulting in shortening of limbs, facial dysmorphia and spinal defects.