While this cross-sectional study was still limited in its predictive power, comparing autosomal dominant and autosomal recessive forms of the disease due to a low number of patients in the non-COL1A1/1A2 group, it supported the prevalence of underlying genetic causes of OI with roughly 90% (n = 268) of our patients carrying COL1A1/1A2 variants which is consistent with well-established incidence data.1 The gene discussed is COL1A1; the disease is osteogenesis imperfecta.