Osteogenesis imperfecta or brittle bone disease is usually caused by mutations in one copy (dominant) or two copies (recessive) of a number of genes.  In order to search for additional disease genes, we enrolled 13 consanguineous families with brittle bone disease and found that three of them map to a novel genetic region which we show harbors a mutation in TMEM38B, known for its function in regulating intracellular calcium level, which we propose to be a novel disease gene.  This finding will expand our understanding of bone development and increase the percentage of families with this disease who can learn the cause of their illness at the gene level. (By Dr Fowzan S Alkuraya, http://jmg.bmj.com/content/49/10/630 )