What does cph4 affect?
There is a metabolic enzyme called 6-carboxytetrahydropterin
synthase or CPH4 synthase that acts as a catalyst in the following
reaction: 7,8-dihydroneopterin 3'-triphosphate + H2O
6-carboxy-5,6,7,8-tetrahydropterin + acetaldehyde + triphosphate To
my knowledge however, it does not affect neurological development
in any way.