My 6 Month Old Has A Recessed Lower Jaw And

My 6 month old has a recessed lower jaw and weak latch. He also has issues with swallowing baby food. His physical therapist has mentioned also that he has a developmental delay both cognitive and physically. We do not know why at this time. There has been no diagnosis. What should I be concerned about? Could he have a genetic disorder causing this? His father and paternal grandmother also have recessed jaw.