Rare diseases · Sign or symptom
Abnormality of the anterior commissure
HP:0030301
What it means
An anomaly of the anterior commissure, a bundle of nerve fibers that connect the two cerebral hemispheres across the midline. The anterior commissure plays a role in pain sensation and contains decussating fibers from the olfactory tracts.
The human brain commissures comprise the corpus callosum, the anterior commissure, the fornix, and the posterior commissure.
Rare diseases that can present with this1
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.
Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.