Dwarfism

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 more than 300 distinct medical conditions. In cases of proportionate dwarfism, the body appears normally proportioned, but is unusually small. The main reason for Dwarfing conditions are frequently referred to as short-limb or short-trunk types. Achondroplasia, hypochondroplasia, and metaphyseal chondrodysplasias are considered short-limb dwarfing conditions.  

The primary defect found in patients with achondroplasia is abnormal endochondral ossification. The iliac crest apophyses are normal, giving rise to large, square iliac wings. Approximately 10,000 individuals are estimated to have achondroplasia. It affects about 1 in every 40,000 children. The worldwide population of little people is approximately 190,000.

The standardized mortality ratio is increased for all age groups by a factor of 2.27 over that of the general population. In individuals aged 5-24 years, central nervous system and respiratory abnormalities are the common causes of death. In persons aged 25-54 years, cardiovascular problems are the most frequent causes of death. Morbidity associated with spinal deformities, obesity, cardiovascular complications, feeding problems.