What Causes Agenesis Of The Corpus Callosum In New Born Baby?

I have a newborn grandson, born 3 and one half weeks early . His mother was in labor 23 hours after her water broke and then she had a CSection. The baby does not cry and will not suck. He is being fed through a feeding tube. The Dr. says that he has Agenisis C Collosum. Is this the reason he is not crying or does not suck. He does not open his eyes often and his oxygen level is in the eighties. He did quit breathing a few times. With this info, can you p lease tell me what all might be wrong.