CLN5 and brachydactyly: Endochondral ossification, the predominant mechanism for limb bone formation, is mediated by factors like SOX9, ROR2, BMPs (Bone Morphogenetic Proteins), GDF5, Indian Hedgehog (IHH), and WNT.[15] Conversely, the distal tips of the phalanges undergo membranous ossification, guided by RUNX2.[4] Genetic mutations underlie brachydactyly, with distinct phenotypes arising from disruptions in endochondral bone formation or skeletal patterning.