- 1 in 40,000 births.
- Second most common lethal skeletal dysplasia, after thanatophoric dysplasia.
- Severe shortening of the limbs, narrow thorax, short trunk length and large head.
- Associated with micrognathia, nuchal edema and polyhydramnios.
- There are 2 types of achondrogenesis:
- Type I (20%): autosomal recessive; there is poor mineralization of the skull and vertebral bodies, as well as rib fractures.
- Type II (80%): sporadic; there is poor mineralization of the vertebral bodies but not the skull and there are no rib fractures.
- Detailed ultrasound examination.
- Achondrogenesis is due to mutations in SLC26A2, COL2A1 and TRIP11 genes.
- If pregnancy continues, follow-up should be standard.
- Standard obstetric care and delivery.
- The condition is lethal due to severe pulmonary hypoplasia.
- Type I: 25%
- Type II: no increased risk.