Craniotabes is softening or thinning of the skull in infants and children, which may be normally present in newborns. It is seen mostly in the occipital and parietal bones. The bones are soft, and when pressure is applied they will collapse underneath it. When the pressure is relieved, the bones will usually snap back into place. The term (cranio- + tabes) is derived from the Latin words cranium for skull and tabes for wasting. Any condition that affects bone growth, most notably rickets (from vitamin D deficiency), marasmus, syphilis, or thalassemia, can cause craniotabes if present during a time of rapid skull growth (most especially during gestation and infancy). It can be a "normal" feature in premature infants. It is the first sign in children and infants with rickets.