Rare diseases · Sign or symptom
Flat face
Flat facial shape
HP:0012368
What it means
Absence of concavity or convexity of the face when viewed in profile.
A useful guide is to imagine that a line connecting the glabella to the anterior most part of the mandible touches the top of the philtrum where it meets the base of the columella. The glabella is the most prominent point on the frontal bone above the root of the nose. If the superior philtrum is anterior to this line the face is convex, if the superior philtrum is posterior to this line the face is concave.
Rare diseases that can present with this69
Very common80–99%
37- Abruzzo-Erickson syndrome
- Achondrogenesis
- Achondrogenesis type 1A
- Achondrogenesis type 1B
- Apert syndrome
- Autosomal recessive Stickler syndrome
- Aymé-Gripp syndrome
- Branchioskeletogenital syndrome
- Campomelic dysplasia
- Camptodactyly syndrome, Guadalajara type 1
- Cleft lip/palate-intestinal malrotation-cardiopathy syndrome
- CODAS syndrome
- Craniofacial-deafness-hand syndrome
- Craniofacial dysostosis-diaphyseal hyperplasia syndrome
- Distal monosomy 7q36 syndrome
- Down syndrome
- Emery-Nelson syndrome
- Flat face-microstomia-ear anomaly syndrome
- Hennekam syndrome
- Larsen syndrome
- Marshall syndrome
- Maxillonasal dysplasia
- Mucopolysaccharidosis type 7
- PDE4D haploinsufficiency syndrome
- Progressive non-infectious anterior vertebral fusion
- Proximal 16p11.2 microduplication syndrome
- Rhizomelic dysplasia, Patterson-Lowry type
- Ring chromosome 7 syndrome
- Short stature-craniofacial anomalies-genital hypoplasia syndrome
- Tetrasomy 5p syndrome
- Thanatophoric dysplasia
- Thanatophoric dysplasia type 1
- Thanatophoric dysplasia type 2
- Thoracomelic dysplasia
- Trisomy 12p syndrome
- X-linked alpha-thalassemia-intellectual disability syndrome
- Zellweger syndrome
Common30–79%
21- 16p11.2p12.2microdeletion syndrome
- 20q11.2microduplication syndrome
- 9q31.1q31.3microdeletion syndrome
- Autosomal recessive otospondylomegaepiphyseal dysplasia
- Camptodactyly syndrome, Guadalajara type 3
- Distal duplication 5q syndrome
- Dyssegmental dysplasia, Silverman-Handmaker type
- Grant syndrome
- Kyphomelic dysplasia
- Lethal Kniest-like dysplasia
- Marfanoid habitus-autosomal recessive intellectual disability syndrome
- Microcornea-glaucoma-absent frontal sinuses syndrome
- Monosomy 22 syndrome
- Mucolipidosis type II
- Rhizomelic chondrodysplasia punctata
- Schwartz-Jampel syndrome
- Short stature-brachydactyly-obesity-global developmental delay syndrome
- Spondylodysplastic Ehlers-Danlos syndrome
- Spondyloepimetaphyseal dysplasia congenita, Strudwick type
- Spondyloepimetaphyseal dysplasia with joint laxity, leptodactylic type
- Spondyloepiphyseal dysplasia congenita
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, and Orphanet separately records 1 disease where this sign is specifically absent. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Flat facial profile · Flat facies
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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.