- 1 in 10,000 births.
- Most common lethal skeletal dysplasia.
- Severe shortening of the limbs, narrow thorax, normal trunk length and large head with prominent forehead.
- There are 2 types of thanatophoric dysplasia:
- Type I (more common): sporadic, the femurs are curved (telephone receiver).
- Type II (rare): sporadic, the femurs are straight but the skull is cloverleaf-shaped.
- Detailed ultrasound examination.
- Thanatophoric dysplasia is due to a mutation in the FGFR3 gene. The diagnosis can be made by invasive testing or cfDNA analysis of maternal blood.
- If pregnancy continues, follow-up should be standard.
- Standard obstetric care and delivery.
- Pregnacies are often complicated by polyhydramnios, prematurity, malpresentation and cephalopelvic dysproporion. The presence of the cloverleaf deformity and hydrocephalus may require cephalocentesis and assisted delivery.
- The condition is lethal due to severe pulmonary hypoplasia.
- No increased risk.