Considering that balanced osteoblast and osteoclast activities determine bone homeostasis, the reduced osteoclastogenesis observed in TRPS1 hypomorphs may also contribute to the presentation of CRS phenotypes under conditions of marginally increased osteogenesis, influenced by the effects of TRPS1 and IL6ST variants on osteoblasts. The gene discussed is IL6ST; the disease is congenital rubella syndrome.