There are over 200 different types of dwarfism, Most types are known as skeletal dysplasias, which are conditions of abnormal bone growth. They're divided into two types: short-trunk and short-limb dysplasias.
People with short-trunk dysplasia have a shortened trunk with longer limbs, whereas those with short-limb dysplasia have an average-sized trunk but small arms and legs. Collectively these types of dwarfism are commonly known disproportionate short stature.
The most common form of disproportionate short stature is known as achondroplasia. This affects 70% of individuals affected by short stature. The average adult height for someone with achondroplasia is about 4 feet.
Primordial dwarfism is a group of disorders in which growth is proportional but extremely delayed, which begins in the womb . This results in some of the smallest people in the world especially in the MOPD disorders (average adult height is less than 2ft 10in).
Primordial dwarfism is not a specific diagnosis. It is in fact a class of disorders to which at least 5 different conditions are currently grouped:
- Majewski Osteodysplastic Primordial Dwarfism Type I/II1
- Majewski Osteodysplastic Primordial Dwarfism Types III
- Russell Silver Syndrome2
- Seckel Syndrome
- Meier-Gorlin Syndrome
The above conditions are the ones that have been medically identified over the last 25 years, however due to ongoing research being carried out by doctors on the WWGF medical review board this may change in the years ahead, if not sooner.
For more information on the specific Primordial Dwarfism sub-types please see the links on the left.
1:Prior to 2010 MOPD I and MOPD II were seperate sub-types however research has now identified that they are the same the condition.
2: The WWGF do not provide support to individuals and families afftected by Russel Silver Syndrome as there are two well established and recognised organisations.
If you are a parent or individual affected by Russell Silver Syndrome, please contact these organisations for advice and support.
Please note the information on the individual pages within the About Primordial Dwarfism menu does not replace individual medical advice or provides a diagnosis. If any parent or guardian visiting this site thinks their child has a form of Primordial Dwarfism, they should consult a local Clinical Geneticist or ask their local pediatrician/doctor to make a referral to one of our doctors on our medical review board.