dwarfism

Abnormally short stature. The most common form is achondroplasia an inherited disorder in which the limbs fail to reach a normal length. The achondroplastic dwarf has short limbs but a head and trunk of normal size.

In pituitary dwarfism there is a deficiency of growth hormone; the pituitary dwarf is physically well proportioned but may be sexually underdeveloped. Intelligence is not affected.

Approximately 90% of achondroplasia cases occur where there is no family history, as a result of a mutation on chromosome 4. The fathers of these children tend to be older than average. The mutation is a dominant trait so it will be passed on to any children.