Rare diseases · Sign or symptom
Vertebrobasilar dolichoectasia
HP:0020038
What it means
Elongation, dilatation, and/or tortuosity of the vertebrobasilar segment. The definition of VBD includes: (i) diameter of basilar or vertebral artery over 4.5 mm; or (ii) deviation of any portion more than 10 mm from the shortest expected course; and (iii) length of basilar artery over 29.5 mm or length of intracranial vertebral artery over 23.5 mm.
The basilar artery arises from the confluence of the two vertebral arteries.
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
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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.