Diastrophic Dwarfism



- Discussion:
    - rare type of skeletal dypslasia characterized by extreme short limb dwarfism, with specific hand, foot, and ear abnormalities;
          - micromelic short-limb dwarfism, cauliflower ears, scoliosis, hitchhiker thumbs, and clubfeet.
          - these individuals have extremely short stature, with a mean adult height of 118 cm;
    - condition was originally referred to as diastrophic dwarfism," which means "crooked or twisted" but was later changed to diastrophic 
          dysplasia in 1977;
    - epiphyseal ossification is delayed, causing flattening & irregularity;
    - may be related to a defect in structure or synthesis of type II collagen in the physis;
    - transmitted as autosomal recessive trait (lesion lies at the distal end of the 5q chromosome);
    - some patients die in infancy but most have a normal life span;
    - intelligence is normal;

- Non Orthopaedic Manifestations:
    - 59% of affected infants have a cleft palate;
    - peculiar ear deformity, cauliflower ear, occurs later in childhood because of a cartilage abnormality;

- Orthopaedic Manifestations:
    - C spine:
            - cervical kyphosis
            - high incidence of quadriplegia;
    - hands:
            - hitchhiker thumb is distinctive feature of dysplasia and is caused by shortening of 1st metacarpal & radial subluxation of 1st MP 
                   joint;
    - spine:
            - surgical treatment is required for curves that continue to progress;
    - hip:
            - at hip, dislocation or DJD are common sequelae of coxa vara and incongruity;
            - hip flexion contracture may be seen in most patients;
    - foot:
            - rigid bilateral equinovarus deformities of feet are typical and are extremely resistant to cast treatment;
            - severe, rigid equinovarus deformity usually requires surgery;
            - symphalangism of the proximal interphalangeal joints of the fingers, and an abducted "hitchhiker's"  thumb are also present



Disorders of the spine in diastrophic dwarfism.

The phenotipic variability of diastrophic dysplasia.

Diastrophic Dwarfism.

Lethal and non-lethal diastrophic dysplasia. A study of 14 Swedish cases.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, May 21, 2012 4:15 pm