Short limbs may be due to many causes. Dysplasia is a term that is used to denote abnormality in maturation of cells within a tissue. That means that the tissue developed would have abnormalities.
The skeletal development can be hampered by many causes and is classified according to the embryological segment affected.
Following types of skeletal dysplasias may cause short limbs
The proximal segment of the limbs is affected. It can be due to
It resembles a mild form of achondroplasia.
Achondroplasia is a common cause of dwarfism. It occurs as a sporadic mutation in approximately 80% of cases or it may be inherited as an autosomal dominant genetic disorder.
Chondrodysplasia punctata has both autosomal dominant and autosomal recessive types. Recessive type is rare.
In autosomal dominant type (Conradi-Hunerman), in the newborn stippling is evident in the long bone epiphyses, spine and larynx. There could be malsegmentation of vertebral bodies. Stippling disappears by 2 years of age and there is asymmetrical shortening of limbs.
These patients usually survive into adulthood.
Autosomal recessive type is marked symmetrical rhizomelia with humeri more severely affected than femora. Spinal stippling is mild. Stillborn or perinatal death.
This is marked by short limb and short spine, marked joint laxity, platyspondyly with exaggerated grooves for the ring apophyses and C1-C2 dislocation.
This involves shortening in the middle segment.
Also known as Leri-Weil disease this is manifested as limb shortening with a Madelung deformity.
Langeresomelic type dysplasia
Reinhardt-Pfeiffer type Dysplasia
This involves middle and distal segment limb shortening
It is also known as Ellis-van Creveld syndrome and is similar to asphyxiating thoracic dysplasia (see below) but with these differences
- Hexadactyly is a constant finding
- There is severe hypoplasia of the fingers and nails
- Congenital heart disease is common and
- Hypoplastic lateral tibial plateau is characteristic
- Nievergelt type
- Robinow type
- Werner type
This involves distal segment shortening
Asphyxiating thoracic dysplasia or Jeune’s syndrome
This is hallmarked by narrow thorax with short ribs leading to respiratory distress. Spur-like projections of the acetabular roof can be found. Premature ossification of the femoral capital epiphyses may occur. Occasional post-axial hexadactyly and cone-shaped epiphyses may occur in childhood.