Dwarf goats are distributed over a very large area of equatorial Africa from the south of the Senegal through Central Africa to Southern Sudan.
Two types of dwarfism occur in goats in Africa.  These are 'achondroplasia' which results in a goat with disproportionally short legs, plump body and short head/neck, and 'pituatary hypoplasia' giiving a small but normally proportioned goat.  The first of these types is typical of the west African dwarf goat found in the Guinean zone of West Africa.  The slender, normally proportioned goat of the second type is found in the Southern Sudan region.  These two types represent the extremes, with many intermediate types in existence. 

The height to withers for both types is given as 40cms to 50cms (approx.16" to 20") with the bodyweight of the West African type ranging from 44lbs to 55 lbs and the Southern Sudan type from 24lbs to 55lbs.  All colours and combinations of colours are said to occur in both types.

The Pygmy Goat Club in Britain does not differentiate between the types.  Upon its formation in 1982 it discarded the regional names in favour of the general term Pygmy Goat.
It is clear that the Pygmy Goat owes more to the West African dwarf than it does to the dwarf goat of Southern Sudan.  It seems likely that the Pygmy Goat is not the extreme form of 'achondroplasic' origin but a transitional type of more pleasing appearance.