Rare diseases · Sign or symptom
Decreased CSF 5-hydroxyindolacetic acid concentration
HP:0025455
What it means
5-HIAA (5-hydroxyindolacetic acid) concentration in the cerebrospinal fluid (CSF) is below the lower limit of normal.
Rare diseases that can present with this2
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
Also called: Decreased CSF 5-HIAA · Low CSF 5-HIAA · Low CSF 5-hydroxyindolacetic acid
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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.