Rare diseases · Sign or symptom
Axial hypotonia
Low muscle tone in trunk
HP:0008936
What it means
Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk.
Rare diseases that can present with this77
Very common80–99%
9- 9q33.3q34.11microdeletion syndrome
- Allan-Herndon-Dudley syndrome
- Brain dopamine-serotonin vesicular transport disease
- GM2 gangliosidosis, AB variant
- Intellectual disability-eye abnormalities-microcephaly-peripheral spasticity syndrome
- Ocular anomalies-axonal neuropathy-developmental delay syndrome
- Posterior-predominant lissencephaly-broad flat pons and medulla-midline crossing defects syndrome
- PRUNE1-related neurological syndrome
- Sandhoff disease, infantile form
Common30–79%
39- Aicardi-Goutières syndrome
- B4GALT1-CDG
- Bilateral generalized polymicrogyria
- Bohring-Opitz syndrome
- COG4-CDG
- Combined oxidative phosphorylation defect type 13
- Combined oxidative phosphorylation defect type 39
- Congenital cataract-progressive muscular hypotonia-hearing loss-developmental delay syndrome
- Congenital cerebellar ataxia due to RNU12 mutation
- Congenital myopathy with myasthenic-like onset
- Cortical dysgenesis with pontocerebellar hypoplasia due to TUBB3 mutation
- DEND syndrome
- Dopa-responsive dystonia due to sepiapterin reductase deficiency
- Dystonia-parkinsonism-hypermanganesemia syndrome
- Early-onset progressive encephalopathy-hearing loss-pons hypoplasia-brain atrophy syndrome
- Early-onset progressive leukoencephalopathy-central nervous system calcification-deafness-visual impairment syndrome
- Familial dyskinesia and facial myokymia
- Hepatoencephalopathy due to combined oxidative phosphorylation defect type 1
- Infantile dystonia-parkinsonism
- Infantile Krabbe disease
- Infantile-onset generalized dyskinesia with orofacial involvement
- Isolated lissencephaly type 1 without known genetic defects
- Lethal ataxia with deafness and optic atrophy
- Leukoencephalopathy with bilateral anterior temporal lobe cysts
- Lissencephaly due to LIS1 mutation
- MFF-related encephalopathy due to mitochondrial and peroxisomal fission defect
- Pelizaeus-Merzbacher disease, classic form
- Phosphoserine aminotransferase deficiency, infantile/juvenile form
- PLA2G6-related neurodegeneration, infantile-onset
- PMM2-CDG
- Pyridoxamine-5-phosphate deficiency-developmental and epileptic encephalopathy
- Pyruvate dehydrogenase phosphatase deficiency
- RARS-related autosomal recessive hypomyelinating leukodystrophy
- SLC35A2-CDG
- Spastic paraplegia-severe developmental delay-epilepsy syndrome
- Sporadic infantile bilateral striatal necrosis
- WARS2-related combined oxidative phosphorylation defect
- X-linked intellectual disability-limb spasticity-retinal dystrophy-arginine vasopressin deficiency
- X-linked intellectual disability, Najm type
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: Muscular hypotonia of the trunk · Truncal hypotonia
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.