ANO5 and Osteopenia: In this study, by measuring genotypes and phenotypes in a GDD family with low bone mass osteopenia, we report a de novo pathogenic ANO5 frameshift insertion mutation (c.1080_1081insGATTATTGGAGACTAAATAGTACGTGTTTG, p.L370_A371insDYWRLNSTCL).