Snyder-Robinson Syndrome (SRS) is a rare disease where patients harbor mutations in the spermine synthase (SMS) gene, resulting in multiple defects, including inadequate bone development. This defect has been suggested to be due to impaired osteogenic differentiation of bone marrow-derived mesenchymal stem cells (MSCs). To elucidate how defective SMS leads to impaired osteogenesis, we generated a lentivirus to deliver shRNA to silence SMS expression. Effective silencing of SMS expression was confirmed by RT-PCR. Interestingly, we found that silencing SMS strongly inhibits cell proliferation. To determine how silencing SMS affects osteogenesis, MSCs were cultured in osteogenic media and assessed for commitment, maturation and mineralization. Commitment is marked by an increase of Runx2 at day 1 of differentiation, however, silencing SMS was shown to have no significant effect on Runx2 expression. Maturation was assessed by analyzing expression of bone sialoprotein (BSP), a major component of the bone extracellular matrix. BSP expression was significantly inhibited in MSCs transduced with shRNA silencing SMS, when compared to controls. Consequently, mineralization in MSCs with shRNA silencing SMS exhibited lower calcium precipitation, as assessed at day 28 using Alazarin Red S staining. To elucidate the underlying mechanisms, mass spectrometry of primary metabolites was performed in MSCs transduced with either control or SMS shRNA. RNAseq studies to determine altered gene expression are currently in progress. In anticipation to improve bone formation in SRS patients, our study aims to more clearly understand the role of SMS, particularly in the context of inefficient osteogenic differentiation of MSCs.