A rare form of autosomal recessive
osteochondrodysplasia characterized by severe dwarfism with marked hypomelia
Grebe Chondrodysplasia; Brazilian Achondrogenesis;
Acromesomelic Dysplasia, Grebe Type; Acromesomelic Dwarfism; Achondrogenesis
Fewer than 100 cases have been described. An
increased frequency has been reported from Bahia, Brazil, where the gene
frequency was evaluated to be 1:50, with a prevalence of 1:2000 live births.
Autosomal recessive as a result of a mutation
in the cartilage-derived morphogenetic protein-1 gene (CDMP1) located on
Based on the clinical findings of severe dwarfism with
marked hypomelia and deformation of upper and lower limbs, with a
proximo-distal gradient of severity. Radiographs show shortening and
deformation of the forearm and foreleg bones, fusion of carpal and tarsal
bones, and absence of proximal and middle phalanges and several metacarpal
and metatarsal bones.
This disorder is limited to the skeleton and
results in short limbs with the arms longer than the legs. The abnormalities
are more severe distally: the humeri and femora are short but normally
shaped, whereas radius/ulna and tibia/fibula are short and deformed, the
carpal and tarsal bones and phalanges are rudimentary, and the metacarpals,
metatarsals, and patellae are hypoplastic or absent. The digits are
consequently very short with a globular appearance connected with a
soft-tissue bridge. Postaxial polydactyly and valgus deformity of hand and
foot are common. The metatarsal, talus, cuneiform, and navicular bones may
be fused. The axial skeleton is normal. An increased frequency of stillbirth
and neonatal death has been reported. No mental retardation.
Routine preoperative assessment.
Check joint mobility for intraoperative positioning.
Anesthesia in this condition has not
been described. The features of the disease suggest that vascular access may
be difficult, and careful intraoperative positioning is required. Regional
anesthesia is not contraindicated but should be expected to be difficult to
perform due to positioning problems.
There are no specific implications
for this condition.
Acromesomelic Dysplasia Maroteaux Type: A very rare, autosomal
recessive inherited disorder that seems to have its highest prevalence on
the south Atlantic island of St. Helena (to which Napoleon was exiled in
1815). Dwarfism is severe and affects mainly the middle and distal parts of
the limbs (progressive shortening of the tubular bones and bowing of radius
and ulna) and the vertebrae (thoracic kyphosis).
Acromesomelic Dysplasia Hunter-Thompson Type: Extremely rare form of
autosomal recessive inherited acromesomelic dysplasia characterized by
severe dwarfism with the abnormalities limited to the limbs (more pronounced
in the lower limbs). Multiple dislocations of the large joints with limited
mobility are common. Patients are mentally normal. The same gene as in
chondrodysplasia Grebe type is responsible for this disorder, although the
mutation affects a different part of the gene. Intelligence seems to be
normal in these patients, although the psychomotor milestones achieved may
be delayed compared to the normal population.