HLS presents itself as various, lethal developmental abnormalities, which often result in either premature stillbirth or death shortly after birth. Rare cases of children born with HLS surviving for several months have been noted. A characteristic abnormality of HLS is an absence of brain tissue and midline structures, with the presence of excess brain fluid (hydrocephalus) as a result of abnormal development of the central nervous system. Other common defects include incomplete lung development, heart defects, a cleft lip or palate, polydactyly, and an abnormally small jaw. Stillbirth and an excess of amniotic fluid (polyhydramnios) are common during pregnancy with a HLS-affected foetus, with cases of up to 8 litres cited compared to the normal 1 litre. Less common symptoms such as abnormally small eyes and a broad nose are also possible.
Hydrolethalus syndrome
Gray baby syndrome
Cantú syndrome
Neonatal encephalopathy
Blue baby syndrome
Foster Kennedy syndrome
Muenke syndrome
Baboon syndrome