To clarify the role(s) for LH3 in collagen biosynthesis, we generated LH3 KO cells using CRIPSR-mediated gene editing to conduct detailed quantitative and molecular analyses of collagens α1α1α2(I), α1α1α1(III), and α1α1α2(IV) implicated in OI, EDS, and Gould syndrome, respectively. This evidence concerns the gene PLOD3 and Ehlers-Danlos syndrome.