kEDS is caused by biallelic pathogenic variants in either PLOD1 or FKBP14. PLOD1 encodes the lysyl hydroxylase 1 enzyme responsible for hydroxylating lysyl residues in the collagen helix, which undergo glycosylation and form crosslinks in the extracellular matrix thus contributing to collagen fibril strength. This evidence concerns the gene FKBP14 and Ehlers-Danlos syndrome, kyphoscoliotic type 1.