PLOD1 and Ehlers-Danlos syndrome: The kyphoscoliotic form of Ehlers-Danlos syndrome is caused by mutations in the PLOD1 gene, which encodes the enzyme procollagen-lysine 1,2-oxoglutarate 5 dioxygenase-1 (PLOD1; also known as lysyl hydroxylase 1) responsible for forming cross-links in collagens via hydroxylysine-based pyridinoline.