Rare diseases · Sign or symptom
Microtia
Small ears
HP:0008551
What it means
Underdevelopment of the external ear.
The definitions of microtia follow a widely used, surgically based, classification of ear anomalies outlined by Weerda 1988. As microtia indicates at least both decreased length and width, and in more severe forms it includes abnormal shape of structures, all forms are acknowledged to be bundled terms, but are retained here because they are well established.
Rare diseases that can present with this89
Very common80–99%
36- Ablepharon macrostomia syndrome
- Acrocephalopolydactyly
- Acrofacial dysostosis, Rodríguez type
- Aspartylglucosaminuria
- Axial mesodermal dysplasia spectrum
- Blepharophimosis-intellectual disability syndrome, Ohdo type
- Camptodactyly syndrome, Guadalajara type 1
- Cerebrofacioarticular syndrome
- Conductive deafness-malformed external ear syndrome
- Coxoauricular syndrome
- Craniosynostosis-hydrocephalus-Arnold-Chiari malformation type I-radioulnar synostosis syndrome
- Cutaneous mastocytosis-deafness-microtia syndrome
- Deafness with labyrinthine aplasia, microtia, and microdontia
- Diabetic embryopathy
- Difference of sex development-intellectual disability syndrome
- Distal deletion 17q syndrome
- Distal deletion 9p syndrome
- Distal Xq28 microduplication syndrome
- Hypertelorism-microtia-facial clefting syndrome
- Isotretinoin-like syndrome
- Isotretinoin syndrome
- Mandibulofacial dysostosis-microcephaly syndrome
- Microphthalmia-microtia-fetal akinesia syndrome
- Microtia-eye coloboma-imperforation of the nasolacrimal duct syndrome
- Monosomy 9p syndrome
- Mycophenolate mofetil embryopathy
- Oculoauriculovertebral spectrum with radial defects
- Postaxial acrofacial dysostosis
- Proximal 16p11.2 microduplication syndrome
- Scalp-ear-nipple syndrome
- Short stature-craniofacial anomalies-genital hypoplasia syndrome
- Tetraamelia-multiple malformations syndrome
- Verloove Vanhorick-Brubakk syndrome
- Wilson-Turner syndrome
- Wolf-Hirschhorn syndrome
- X-linked intellectual disability, Van Esch type
Common30–79%
26- 17q24.2microdeletion syndrome
- 20q11.2microduplication syndrome
- 3-hydroxyisobutyric aciduria
- Acitretin/etretinate embryopathy
- Atrioventricular defect-blepharophimosis-radial and anal defect syndrome
- Aymé-Gripp syndrome
- Craniofacial microsomia
- Craniosynostosis, Herrmann-Opitz type
- Dysmorphism-short stature-deafness-difference of sex development syndrome
- Femoral-facial syndrome
- FG syndrome type 1
- Isolated arrhinia
- Johnson neuroectodermal syndrome
- Kagami-Ogata syndrome due to paternal uniparental disomy of chromosome 14
- Microcephalic primordial dwarfism, Dauber type
- Mosaic trisomy 14 syndrome
- Nager syndrome
- Oculoauriculofrontonasal syndrome
- Pallister-Hall syndrome
- Pelvis-shoulder dysplasia
- Saethre-Chotzen syndrome
- Short ulna-dysmorphism-hypotonia-intellectual disability syndrome
- Spondyloepiphyseal dysplasia-brachydactyly-speech disorder syndrome
- Townes-Brocks syndrome
- Treacher-Collins syndrome
- XY type gonadal dysgenesis-associated anomalies syndrome
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: Bilateral microtia · Hypoplasia of the external ear · Hypoplastic ears · Hypoplastic pinna · Small pinnae · Underdeveloped ears
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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.