achondroplasia
/eɪˌkɑndrəˈpleɪʒ(i)ə/
noun
A hereditary condition in which the growth of long bones by ossification of cartilage is retarded, resulting in very short limbs and sometimes a face that is small in relation to the (normal-sized) skull.
This phenomenon has been described in osteogenesis imperfecta, achondroplasia and Duchenne muscular dystrophy.