Rare diseases · Sign or symptom
Brachycephaly
Short and broad skull
HP:0000248
What it means
An abnormality of skull shape characterized by a decreased anterior-posterior diameter. That is, a cephalic index greater than 81%. Alternatively, an apparently shortened anteroposterior dimension (length) of the head compared to width.
Cephalic index is the ratio of head width expressed as a percentage of head length. The normal range is 76-80.9%. Head length is measured between the glabella (the most prominent point on the frontal bone above the root of the nose) and the most prominent part of the occiput in the midline, using spreading calipers. Head width is measured between the most lateral points of the parietal bones on each side of the head, using spreading calipers. Cephalic index standards are derived from Caucasians and have limited relevance for other races and ethnicities. Current norms also have limited validity because of changes in infant sleeping position and consequent changes in head shape. New data should be developed. Brachycephaly is distinct from Flat occiput, but both can be present in the same individual and should be coded separately.
Rare diseases that can present with this136
Very common80–99%
50- Acrofrontofacionasal dysostosis
- Acromelic frontonasal dysplasia
- Adenylosuccinate lyase deficiency
- AICA-ribosiduria
- Antley-Bixler syndrome
- Baller-Gerold syndrome
- Branchioskeletogenital syndrome
- Cerebrofaciothoracic dysplasia
- Cerebrooculonasal syndrome
- CHIME syndrome
- Cooper-Jabs syndrome
- Cornelia de Lange syndrome
- Craniodigital-intellectual disability syndrome
- Craniofrontonasal dysplasia
- Craniosynostosis-anal anomalies-porokeratosis syndrome
- Craniosynostosis, Herrmann-Opitz type
- Craniosynostosis-hydrocephalus-Arnold-Chiari malformation type I-radioulnar synostosis syndrome
- De Barsy syndrome
- Down syndrome
- Fetal trimethadione syndrome
- Frontonasal dysplasia-alopecia-genital anomalies syndrome
- Fucosidosis
- German syndrome
- Gómez-López-Hernández syndrome
- Gorlin-Chaudhry-Moss syndrome
- Hallermann-Streiff syndrome
- Holoprosencephaly-craniosynostosis syndrome
- Hypertelorism-hypospadias-polysyndactyly syndrome
- Intellectual disability-obesity-brain malformations-facial dysmorphism syndrome
- Intellectual disability-seizures-hypophosphatasia-ophthalmic-skeletal anomalies syndrome
- Kleefstra syndrome due to 9q34 microdeletion
- Marshall syndrome
- Microbrachycephaly-ptosis-cleft lip syndrome
- Microcephaly-microcornea syndrome, Seemanova type
- Monosomy 9p syndrome
- Neurofaciodigitorenal syndrome
- Non-syndromic bicoronal craniosynostosis
- Oculocerebrofacial syndrome, Kaufman type
- Osteogenesis imperfecta
- Osteosclerosis-developmental delay-craniosynostosis syndrome
- Peters plus syndrome
- Pfeiffer syndrome type 1
- Potocki-Shaffer syndrome
- Progressive non-infectious anterior vertebral fusion
- Ring chromosome 7 syndrome
- Roberts syndrome
- Severe microbrachycephaly-intellectual disability-athetoid cerebral palsy syndrome
- Smith-Magenis syndrome
- Spondyloepiphyseal dysplasia-craniosynostosis-cleft palate-cataracts-intellectual disability syndrome
- Trisomy 9p syndrome
Common30–79%
30- 14q22q23microdeletion syndrome
- 19p13.12microdeletion syndrome
- 1p36deletion syndrome
- 2p15p16.1microdeletion syndrome
- 2q23.1microdeletion syndrome
- 7q11.23microduplication syndrome
- 8q12microduplication syndrome
- 9p13microdeletion syndrome
- Acrodysostosis
- Autosomal recessive faciodigitogenital syndrome
- Aymé-Gripp syndrome
- Camptodactyly syndrome, Guadalajara type 1
- Cataract-intellectual disability-hypogonadism syndrome
- Congenital muscular dystrophy, Fukuyama type
- Craniofacial dysostosis-diaphyseal hyperplasia syndrome
- Crouzon syndrome
- Crouzon syndrome-acanthosis nigricans syndrome
- Distal deletion 3p syndrome
- Early-onset seizures-distal limb anomalies-facial dysmorphism-global developmental delay syndrome
- Frontofacionasal dysplasia
- Grant syndrome
- Hereditary sensory and autonomic neuropathy due to TECPR2 mutation
- Hypomandibular faciocranial dysostosis
- Infantile multisystem neurologic-endocrine-pancreatic disease
- Intellectual disability-hypotonia-brachycephaly-pyloric stenosis-cryptorchidism syndrome
- Kleefstra syndrome
- LIG4 syndrome
- Microcephaly-facial dysmorphism-ocular anomalies-multiple congenital anomalies syndrome
- MOMO syndrome
- Monosomy 18p 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: Broad cranium shape · Broad head shape · Broad skull shape · Wide cranium shape · Wide head shape · Wide skull shape
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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.