++
Very rare inherited disorder characterized by short
stature with abnormally short arms and legs (short-limbed dwarfism). Other
physical characteristics may include outward “flaring” of the lower rib
cage, genu varum, pain in the legs, and/or hip deformities (coxa vara). Such
abnormalities of the legs and hips typically result in an unusual
“waddling” gait.
++
Metaphyseal Dysplasia, Schmid Type; Schmid Metaphyseal
Dysplasia.
++
Congenital anomaly of collagen located in the metaphyses.
++
Autosomal dominant with variable expression;
de novo mutations not rare.
++
Mutation in COL10A1 gene for collagen type X, the
expression of which is restricted to the hypertrophic zone of the growth
plate. This explains the metaphyseal location of the disease and the
mechanical weakness of the growth plates in these patients.
++
Clinical picture, but rickets and causes of
hypophosphatasemia should be excluded.
++
Moderate short stature, bowed legs, coxa vara,
waddling gait. Irregular metaphyses, but the radiological picture can temporarily
disappear after prolonged bed rest. Enlarged femoral capital epiphyses. No
vertebral anomalies. Adult height: approximately 130 to 160 cm (51.2-63
inches).
++
Because of the numerous skeletal
anomalies, positioning of the patient must require special attention.
Lachman RS, Rimoin DL, Spranger J: Metaphyseal chondrodysplasia, Schmid
type. Clinical and radiographic delineation with a review of the literature.
Pediatr Radiol 18:93, 1988.
[PubMed: 3281118]