In brief…  

Achondroplasia as a type of dwarfism. It’s generally referred to as disproportionate dwarfism as people with the condition have a near normal trunk length however, their arms and legs tend to be much shorter and usually involves a multitude of other health conditions.

Achondroplasia is a rare condition and is estimated to occur in 1 in every 25,000 births according to the RGA. Children with Achondroplasia are often born to parents of average height.

Much more information can be found on the RGA website here, or Little People UK’s site here.