Dwarfism occurs when an individual person or animal is short in stature resulting from a medical condition caused by abnormal (slow or delayed) growth. In humans, dwarfism is sometimes defined as an adult height of less than 4 feet 10 inches (58 in; 147 cm). Dwarfism can be caused by about 200 distinct medical conditions, such that the symptoms and characteristics of individuals with dwarfism vary greatly. Disproportionate dwarfism is characterized by one or more body parts being relatively large or small in comparison to those of an average-sized adult, with growth variations in specific areas being apparent. In cases of proportionate dwarfism, the body appears normally proportioned, but is unusually small.