The diagnosis is made based on the clinical findings
of micromelic dwarfism (distal hypoplasia of the humeri and femora),
hypoplasia of the midthoracic spine, histology results (multiple degenerated
chondrocytes that are encapsulated in fibrous tissue; resting cartilage appears
intact, but hypocellular areas with multinucleated chondrocytes are
interspersed with areas of normal cellularity), and radiologic signs. All
reported cases have been stillborn or died soon after birth secondary to
respiratory failure. Clinical features involve head and neck (facial
hemangiomas, frontal bossing, prominent globes, edematous eyelids, depressed
nasal bridge, nose and midface hypoplasia, micrognathia, cleft palate, short
neck), the airway (laryngeal stenosis, small tunnel chest, missing ribs),
the limbs (distal humeral and femoral hypoplasia, knee/elbow subluxation,
talipes equinovarus, hypoplastic/absent fibulae, bowed radius/fibulae,
phalangeal mineralization defects), and the axial skeleton (cervical fusion
of vertebrae, midthoracic spine hypoplasia with platyspondyly, sagittal and
coronal clefting). Encephaloceles have been reported.