The full answer
Yes — siblings share the same elevated risk as other first-degree relatives
Siblings of someone with celiac disease carry a similarly elevated risk to parents and children, since they share a comparable degree of genetic overlap — testing is generally recommended even without symptoms.
Symptoms aren't a reliable filter
Because celiac disease can be present without obvious symptoms, waiting for symptoms to appear before testing a sibling isn’t a reliable approach — proactive testing catches more cases.
Important context
Individual symptoms, reactions, medical histories, food products, and local labeling rules can vary. Community experiences are not medical evidence.
For personal medical decisions, diagnosis, testing, or treatment, consult a qualified healthcare professional.