Thanatophoric dysplasia: antenatal ultrasound


Thanatophoric dysplasia is also known as lethal skeletal dysplasia, thanatophoric dwarfism, and lethal osteochondrodysplasia.

Thanatophoric dysplasia is a lethal skeletal dysplasia due to mutation of fibroblast growth factor receptor 3 gene (FGFR3).

Ultrasonographic findings

  • long bones severely affected; micromelia is present; may have prominent bowing 
  • ossification is normal and no evidence of fractures (differential of osteogenesis imperfecta)
  • relatively normal shaped head; may be macrocephalic and may have midline hypoplasias
  • small narrow thorax due to short ribs, which leads to hypoplastic lungs and abnormal cardiothoracic ratio
  • heart, spine and abdomen are normal