Rare diseases · Sign or symptom
Absent Achilles reflex
Absent ankle reflexes
HP:0003438
What it means
Absence of the Achilles reflex (also known as the ankle jerk reflex), which can normally be elicited by tapping the tendon is tapped while the foot is dorsiflexed.
Rare diseases that can present with this21
Very common80–99%
3Common30–79%
7Sometimes5–29%
10- Autosomal dominant Charcot-Marie-Tooth disease type 2W
- Autosomal dominant optic atrophy and cataract
- Autosomal dominant optic atrophy plus syndrome
- Autosomal dominant spastic paraplegia type 9B
- Autosomal recessive spastic ataxia of Charlevoix-Saguenay
- Autosomal recessive spastic paraplegia type 9B
- Distal myopathy with anterior tibial onset
- Isolated posterior meningocele
and 2 more in this range
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.