COL1A1 and osteogenesis imperfecta: The data from the present study suggest that this distinction between the α1- and α2-collagen chain is not so strict, since, on the one hand, our patients with a COL1A1 mutation display a milder, more EDS-like phenotype than the patient cohort reported by Cabral et al.[7] and, on the other hand, no significant difference in aspect or severity of the OI/EDS phenotype is observed between the patients with an α1(I)- versus an α2(I)-chain mutation.