hemifacial myohyperplasia
Findings
No curated finding names hemifacial myohyperplasia yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Hemifacial myohyperplasia (HMH) is a developmental disorder that frequently affects the right side of the face and is commonly seen in males. On the affected side of the face, there are usually enlarged tissues that lead to an abnormal jaw shape. Other features associated with HMH include enlargement of the brain, epilepsy, strabismus, genitourinary system disorders, intellectual disability, and dilation of the pupil on the affected side. Asymmetry of the face is more noticeable with age and remains until the end of adolescence when the asymmetry stabilizes. The cause of HMH is unknown; but theories suggest an imbalance in the endocrine system, neuronal abnormalities, chromosomal abnormalities, random events in twinning and fetal development, and vascular or lymphatic abnormalities.
Definition from the Mondo Disease Ontology (MONDO:0011723), read 2026-09-29. CC BY 4.0.
- Inheritance
- Typified by somatic mosaicism
- Onset and course
- Congenital onset
HPO, annotations 2026-09-02
Features
5 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.
- Dimple chinHPOHP:0010751
- 5 of 5 reported patients
- Hemifacial hypertrophyHPOHP:0005323
- 5 of 5 reported patients
- Narrow palpebral fissureHPOHP:0045025
- 4 of 5 reported patients
- PtosisHPOHP:0000508
- 4 of 5 reported patients
- Deviated nasal septumHPOHP:0004411
- 3 of 5 reported patients