With this series, we also confirmed a low frequency of PLS3 and WNT1 mutations in patients showing the first fractures in infancy, with a bone phenotype similar to those with COL1A2. 10, 26, 27 The characterization of a genetic background in idiopathic osteoporosis was facilitated by the use of NGS sequencing, which would not have been possible by Sanger sequencing targeting collagen I only. The gene discussed is COL1A2; the disease is idiopathic juvenile osteoporosis.