Deficiency of spermine synthase causes excessive spermidine accumulation and a lack of spermine.141 Patients with Snyder-Robinson syndrome, a syndrome caused by loss-of-function mutations of the spermine synthase gene, exhibit severe OP and kyphoscoliosis and have BMSCs with impaired capacities for osteogenic differentiation and mineralization.142. This evidence concerns the gene SMS and Kyphoscoliosis.