Granulomatosis with polyangiitis (GPA) — formerly called Wegener's granulomatosis — is among the most confounding autoimmune diagnoses a person can receive. It attacks small and medium blood vessels through a combination of necrotizing granulomatous inflammation and vasculitis, typically beginning in the upper respiratory tract before involving the lungs and kidneys.

If you or your child has been diagnosed with tricho-rhino-phalangeal syndrome (TRPS), you have probably already noticed a gap: most of what you find online describes what the condition looks like, but very little explains what is actually happening at the molecular level, or what a family can realistically track and act on over time.