In contrast, PUMC-OI-147, with a deletion of the intron in COL1A2 (c.2350-87_2350-124del), exhibited severe clinical symptoms (type III OI), including extremely short statures (Z-score, −12.87) and high-frequency fractures (≥ 60 times) (Table S1). This evidence concerns the gene COL1A2 and osteogenesis imperfecta.