neurodevelopmental disorder with hypotonia and variable intellectual and behavioral abnormalities
Findings
No curated finding names neurodevelopmental disorder with hypotonia and variable intellectual and behavioral abnormalities yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Neurodevelopmental disorder in which the cause of the disease is a variation in the POLR2A gene; it is characterized by early-onset hypotonia, delayed walking, poor speech, and impaired intellectual development. Other features may include feeding difficulties, dysmorphic features, and visual problems. Brain magnetic resonance imaging tends to show delayed myelination, thin corpus callosum, and/or enlarged ventricles.
Definition from the Mondo Disease Ontology (MONDO:0032829), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance · Typically de novo
HPO, annotations 2026-09-02
Features
33 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Generalized hypotoniaHPOHP:0001290
- 14 of 15 reported patients
- StrabismusHPOHP:0000486
- 11 of 15 reported patients
- Exercise intoleranceHPOHP:0003546
- 10 of 14 reported patients
- Feeding difficultiesHPOHP:0011968
- 10 of 14 reported patients
- Frog-leg postureHPOHP:0031139
- 10 of 15 reported patients · Infantile onset
- Recurrent respiratory infectionsHPO
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- POLR2AHGNC:9187
- Definitive · ClinGen · Autosomal dominant · 2024
- Definitive · G2P · Autosomal dominant · 2025
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2022
- Strong · Broad Center for Mendelian Genomics · Autosomal dominant · 2019
- Strong · PanelApp Australia · Autosomal dominant · 2025
- Moderate · Ambry Genetics · Autosomal dominant · 2023
Where it sits
Other names
4 names
Resolves to: neurodevelopmental disorder with hypotonia and variable intellectual and behavioral abnormalities
- Also called
- NEDHIBPOLR2A-associated neurodevelopmental disabilityPOLR2A-related disorderPOLR2A-Related Disorders