My son is still undiagnosed genetics are worried

Hi everyone .. I had my son20 months ago and he had IUGR .. I delivered vaginaly at 34 weeks and he was 3lbs although he could breath on his own he had bigger problems he had big bulging wide open fontanelles and his liver enzymes were trough the roof! After 2 biopsies they're still not sure what is wrong so he gets urso to help his liver function... He is seen by a genetics de and he is sure at 90% that this is a genetics disorder but he still cant find it! They also did a couple of MRI's and they told us sebastian has brain atrophy! I did a lot of research and wanted the dr's to check him for hydrocephalus because of his bulging fontanelles constant vomiting and really low muscle tone ( no coordination whatsoever) they did... A lumbar puncture and it came back ok... I just couldnt believe that so i pushed and pushed until they did another test i had the help of my ophtalmolpgist because he was now having atrophy nerve in his eyes which led to some pressure in te brain! So they did another test and this one was directly in the brain... He was at 19 pressure and normaly it's at 10 so he had some pressure they did the shunt... He still has bulging fontanelles and they still didnt close ! His head circ is 56 cm and he weights 11kg 74 cm
long ... He is still vomiting like crazy and is tube fed i wonder if anyone knows what kind of a syndrome this can be? I am pregnant with my 2 one and am so scared i also think genetics somehow put us aside... normaly it's at 10 so he had some pressure they did the shunt... Sebastian still has bulging fontanelles and they still didnt close ! His head circ is 56 cm and he weights 11kg 74 cm long ... He is still vomiting like crazy and is tube fed i wonder if anyone knows what kind of a syndrome this can be? I am pregnant with my 2 one and am so scared i also think genetics somehow put us aside...I was told that abortion might be a solution but i dont want that ... Plz help if u know what is syndrom is