@elynnbish, welcome. Being a "medical mom" advocating for your son is a full time job - as in 24/7 full time - not to mention the emotional burden to see your child in pain with few solutions.

@frances007 @zebra2022 @19kcm56 @goddard and others have shared their experiences in this related discussion and may have thoughts to share with you.
– Hypogammaglobulinemia
https://connect.mayoclinic.org/discussion/hypogammaglobulinemia/
Were they able to determine if your son's hypogammaglobulinemia was caused by genetics or started at birth (primary immune deficiencies)? Or if it is the result of another condition, called secondary or acquired immune deficiencies?