COL1A2 and osteogenesis imperfecta: OI is known to have a frequency of approximately 1:15–20,000, and it is determined that the vast majority of patient cases (~90%) are caused by autosomal dominant pathogenic variants in the collagen type I α 1 chain (COL1A1, OMIM#: 120150) and collagen type I α 2 chain (COL1A2, OMIM#: 120160) producing collagen type I [3].