Rare diseases · Sign or symptom
Neonatal hypotonia
Low muscle tone, in neonatal onset
HP:0001319
What it means
Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period.
Rare diseases that can present with this80
Very common80–99%
21- 15q overgrowth syndrome
- 1q41q42microdeletion syndrome
- Congenital hyperinsulinism due to HNF4A deficiency
- Developmental delay-language impairment-dopa responsive dystonia-parkinsonism syndrome due to 2q24 microdeletion
- Distal 16p11.2 microdeletion syndrome
- Houge-Janssens syndrome type 1
- Hyperinsulinism due to HNF1A deficiency
- Hyperinsulinism due to short chain 3-hydroxylacyl-CoA dehydrogenase deficiency
- KAT6-related intellectual disability-craniofacial anomalies-cardiac defects syndrome
- Kyphoscoliotic Ehlers-Danlos syndrome due to lysyl hydroxylase 1 deficiency
- Multiple sulfatase deficiency
- Oculocerebrorenal syndrome of Lowe
- Phelan-McDermid syndrome
- Polymicrogyria with optic nerve hypoplasia
- Schaaf-Yang syndrome
- TBCK-related encephalopathy-severe hypotonia-craniofacial dysmorphism syndrome
- Tetrasomy 5p syndrome
- X-linked intellectual disability, Cantagrel type
- Xp21deletion syndrome
- X small rings syndrome
- Zebra body myopathy
Common30–79%
37- 47,XYY syndrome
- 6q16microdeletion syndrome
- Amish nemaline myopathy
- B3GALT6-related spondylodysplastic Ehlers-Danlos syndrome
- Birk-Barel syndrome
- Combined immunodeficiency with facio-oculo-skeletal anomalies
- Congenital hypothyroidism due to maternal intake of antithyroid drugs
- Congenital muscular dystrophy without intellectual disability
- Congenital-onset Steinert myotonic dystrophy
- Emery-Nelson syndrome
- Facial dysmorphism-developmental delay-behavioral abnormalities syndrome due to 10p11.21p12.31 microdeletion
- Facial dysmorphism-developmental delay-behavioral abnormalities syndrome due to WAC point mutation
- Global developmental delay-alopecia-macrocephaly-facial dysmorphism-structural brain anomalies syndrome
- Hao-Fountain syndrome due to 16p13.2 microdeletion
- Hypotonia-speech impairment-severe cognitive delay syndrome
- Infantile multisystem neurologic-endocrine-pancreatic disease
- Isolated lissencephaly type 1 without known genetic defects
- Kyphoscoliotic Ehlers-Danlos syndrome
- Malan overgrowth syndrome
- Maternal uniparental disomy of chromosome 1 syndrome
- Moderate multiminicore disease with hand involvement
- Monosomy 18q syndrome
- Non-progressive cerebellar ataxia with intellectual disability
- Paramyotonia congenita of Von Eulenburg
- Paternal uniparental disomy of chromosome 1 syndrome
- Prader-Willi syndrome due to imprinting mutation
- Prader-Willi syndrome due to translocation
- Progressive encephalopathy with leukodystrophy due to DECR deficiency
- Pyruvate dehydrogenase phosphatase deficiency
- Sepsis in premature infants
- Severe congenital nemaline myopathy
- Severe neonatal hypotonia-seizures-encephalopathy syndrome due to 5q31.3 microdeletion
- SIM1-related Prader-Willi-like syndrome
- Spinocerebellar ataxia type 7
- Temple syndrome due to paternal 14q32.2 microdeletion
- Typical nemaline myopathy
- X-linked centronuclear myopathy
Sometimes5–29%
19- 6q25.2q25.3microdeletion syndrome
- Allan-Herndon-Dudley syndrome
- Atypical Rett syndrome
- Autosomal recessive ataxia, Beauce type
- Brachydactyly-short stature-retinitis pigmentosa syndrome
- Brittle cornea syndrome
- Congenital hypothyroidism due to transplacental passage of TSH-binding inhibitory antibodies
- Laminin subunit alpha 2-related congenital muscular dystrophy
and 11 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
Also called: Congenital hypotonia · Hypotonia, in neonatal onset · Hypotonia, neonatal
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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.