Hydrolethalus syndrome is a rare lethal genetic syndrome characterized by multiple developmental defects of fetus which include
- midline malformations
- CNS malformations
- micrognathia / microgenia
- fetal limb anomalies
The estimated incidence is at approximately 1 in 20000 births. There is often ancestral links to an area in eastern Finland where the syndrome was described, for the first time, in 1981. Outside of this sub group, the incidence is even much more rarer.
An autosomal recessive inheritance pattern is often suspected and it is thought to be caused by a missense mutation in a novel gene HYLS1.
- fetal hydrocephalus