Rare diseases · Sign or symptom
Frontal bossing
HP:0002007
What it means
Bilateral bulging of the lateral frontal bone prominences with relative sparing of the midline.
This is not the same as prominent forehead.
Rare diseases that can present with this235
Very common80–99%
79- 17p13.3microduplication syndrome
- 1q41q42microdeletion syndrome
- 2p21microdeletion syndrome
- 3C syndrome
- 3M syndrome
- Achondrogenesis
- Achondrogenesis type 1A
- Achondrogenesis type 1B
- Albers-Schönberg osteopetrosis
- Alexander disease
- Aniridia-renal agenesis-psychomotor retardation syndrome
- Antley-Bixler syndrome
- Apert syndrome
- Autosomal recessive omodysplasia
- B3GALT6-related spondylodysplastic Ehlers-Danlos syndrome
- Baller-Gerold syndrome
- Cenani-Lenz syndrome
- Cleidocranial dysplasia
- Cloverleaf skull-multiple congenital anomalies syndrome
- Coffin-Lowry syndrome
- Cole-Carpenter syndrome
- Cooper-Jabs syndrome
- Craniodiaphyseal dysplasia
- Cranioectodermal dysplasia
- Craniofrontonasal dysplasia
- Craniolenticulosutural dysplasia
- Craniosynostosis-anal anomalies-porokeratosis syndrome
- Craniosynostosis-Dandy-Walker malformation-hydrocephalus syndrome
- Craniotelencephalic dysplasia
- Crouzon syndrome
- Crouzon syndrome-acanthosis nigricans syndrome
- Cystic fibrosis-gastritis-megaloblastic anemia syndrome
- Deafness-craniofacial syndrome
- Delayed membranous cranial ossification
- Dermotrichic syndrome
- Dysmorphism-pectus carinatum-joint laxity syndrome
- Early-onset parkinsonism-intellectual disability syndrome
- Ectodermal dysplasia-intellectual disability-central nervous system malformation syndrome
- Edinburgh malformation syndrome
- Familial intestinal malrotation
- Fibulo-ulnar hypoplasia-renal anomalies syndrome
- GAPO syndrome
- Grant syndrome
- Hallermann-Streiff syndrome
- Hurler syndrome
- IMAGe syndrome
- Intellectual disability-polydactyly-uncombable hair syndrome
- Intellectual disability-short stature-hypertelorism syndrome
- Isolated megalencephaly
- Linear nevus sebaceus syndrome
- Megalocornea-intellectual disability syndrome
- Microcephalic osteodysplastic dysplasia, Saul-Wilson type
- Microphthalmia-microtia-fetal akinesia syndrome
- Microphthalmia with limb anomalies
- Mosaic trisomy 14 syndrome
- Multiple epiphyseal dysplasia-macrocephaly-facial dysmorphism syndrome
- Non-distal duplication 10q syndrome
- Non-syndromic bilambdoid and sagittal craniosynostosis
- Opsismodysplasia
- Orofaciodigital syndrome type 1
- Pituitary gigantism
- Progressive spondyloepimetaphyseal dysplasia-short stature-short fourth metatarsals-intellectual disability syndrome
- Pycnodysostosis
- Ring chromosome 10 syndrome
- Ring chromosome 8 syndrome
- Schinzel-Giedion syndrome
- Severe microbrachycephaly-intellectual disability-athetoid cerebral palsy syndrome
- Short stature-craniofacial anomalies-genital hypoplasia syndrome
- SIX2-related frontonasal dysplasia
- Smith-Magenis syndrome
- Thin ribs-tubular bones-dysmorphism syndrome
- Trichorhinophalangeal syndrome type 1
- Trisomy 5p syndrome
- Unilateral ocular duplication
- White matter hypoplasia-corpus callosum agenesis-intellectual disability syndrome
- Wiedemann-Rautenstrauch syndrome
- Wolf-Hirschhorn syndrome
- X-linked dominant chondrodysplasia, Chassaing-Lacombe type
- Zellweger-like syndrome without peroxisomal anomalies
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: Frontal protuberance · Skull bossing
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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.