A Patient with Bone Fragility, Multiple Fractures, Osteosarcoma, and the Variant c.143A>G in the IFITM5 Gene: A Case Report.

Osteogenesis imperfecta (OI) is a group of genetic skeletal disorders, with a prevalence of 1 in 15,000-20,000 births. OI type V has been described in approximately 150 cases and all patients carry the variant (c.-14C> T) in the IFITM5 gene. However, two other variants, p.S40L and p.N48S have been reported in this gene, leading to clinical phenotypes different from OI type V. Here we described a patient with multiple bone fractures, scoliosis, skull alteration (plagiocephaly), bone deformation, bone rickets, and intramedullary epithelioid osteosarcoma that bears the recently reported heterozygous variant c.143A>G (p.N48S) in the IFITM5 gene. This case supports the pathogenicity of this new variant in the IFITM5 gene and adds information regarding its clinical phenotype.