Nanism

noun

2. Aberration from normal form by decrease in size; the character or quality of being dwarfed or pygmy; dwarfishness: opposed to gigantism.
3. The condition of being abnormally small in stature; dwarfism; dwarfishness; -- opposed to gigantism.
4. Unusually small size, as a result of a developmental abnormality
5. a genetic abnormality resulting in short stature