In 2019, the proband consulted a geneticist at the Research center for medical genetics, who suggested the presumptive diagnosis of osteogenesis imperfecta type I. Molecular genetic testing using the massively parallel signature sequencing method that involved the analysis of the 17 genes currently associated with osteogenesis imperfecta (BMP1, COL1A1, COL1A2, CREB3L1, CRTAP, FKBP10, IFITM5, LEPRE1, PLOD2, PLS3, PPIB, SERPINF1, SERPINH1, SP7, SPARC, TMEM38B, WNT1) showed no pathogenic variants. The gene discussed is COL1A2; the disease is osteogenesis imperfecta.