Lu Y, et al. - Researchers reported whether biallelic mutations in WNT1 can account for a rare form of moderate to severe osteogenesis imperfecta (OI) in children (age 2 to 16-years; 5 girls). Loss of WNT1 function is caused by the reported biallelic WNT1 variants. It leads to a severe bone fragility phenotype with conspicuous involvement of the spine. Structural modifications were led by the missense mutations; as seen on 3-dimensional protein modeling. A variation from -7.2 to +1.5 was seen in height z-scores.