Unibrow

Genetics

The unibrow is a genetic trait.^[15] It is associated with the PAX3 gene.^[16]

Medical conditions

A unibrow is part of normal human variation, but can also stem from developmental disorders. A unibrow is a recognized feature of Cornelia De Lange syndrome, a genetic disorder whose main features include moderate to severe learning difficulties, limb abnormalities such as oligodactyly (fewer than normal fingers or toes), and phocomelia (malformed limbs), and facial abnormalities including a long philtrum (the slight depression/line between the nose and mouth).

Other medical conditions associated with a unibrow include:^[17]

• 3MC syndrome 1
• Acromegaloid facial appearance syndrome
• Acromesomelic dysplasia 4
• Amaurosis-hypertrichosis syndrome
• Arrhinia with choanal atresia and microphthalmia syndrome
• Autosomal recessive spinocerebellar ataxia 17
• Blepharophimosis-impaired intellectual development syndrome
• Blepharophimosis-ptosis-esotropia-syndactyly-short stature syndrome
• Brachycephaly, trichomegaly, and developmental delay
• Chromosome 1p36 deletion syndrome
• Coffin-Siris syndrome 12
• Cognitive impairment – coarse facies – heart defects – obesity – pulmonary involvement – short stature – skeletal dysplasia syndrome
• Congenital muscular hypertrophy-cerebral syndrome

• Cornelia de Lange syndrome 1–5
• Corpus callosum agenesis-abnormal genitalia syndrome
• Cortical dysplasia, complex, with other brain malformations 11
• Deafness, cataract, impaired intellectual development, and polyneuropathy
• Deficiency of transaldolase
• DeSanto-Shinawi syndrome due to WAC point mutation
• Developmental and epileptic encephalopathy 23, 66, 83, 84, 85 (with or without midline brain defects), 100, and 105 (with hypopituitarism)
• Developmental delay with variable intellectual disability and dysmorphic facies
• Developmental delay, impaired speech, and behavioral abnormalities
• Diamond-Blackfan anemia 21
• Early-onset progressive diffuse brain atrophy-microcephaly-muscle weakness-optic atrophy syndrome
• Epilepsy, X-linked 2, with or without impaired intellectual development and dysmorphic features
• Epilepsy-telangiectasia syndrome
• Focal segmental glomerulosclerosis and neurodevelopmental syndrome
• Fontaine progeroid syndrome
• Goldberg-Shprintzen megacolon syndrome
• Growth delay due to insulin-like growth factor I resistance
• Hajdu-Cheney syndrome
• Hennekam lymphangiectasia-lymphedema syndrome 3
• Holoprosencephaly 5, 7, and 11

• Hypotonia, ataxia, and delayed development syndrome
• Intellectual developmental disorder 61
• Intellectual developmental disorder with or without peripheral neuropathy
• Intellectual developmental disorder, autosomal dominant 64 and 65
• Intellectual developmental disorder, autosomal recessive 68
• Intellectual developmental disorder, X-linked, syndromic, with pigmentary mosaicism and coarse facies
• Intellectual disability, autosomal dominant 29, 30, 34, 43, 48, and 52
• Intellectual disability, autosomal recessive 5, 13, 16, 45, 46, and 61
• Intellectual disability, X-linked 21, 73, 97, and 106
• Intellectual disability, X-linked, syndromic 33
• Intellectual disability-brachydactyly-Pierre Robin syndrome
• Intellectual disability-facial dysmorphism syndrome due to SETD5 haploinsufficiency
• Joubert syndrome 35
• KBG syndrome
• Kleefstra syndrome 1
• Lissencephaly 6 with microcephaly
• Macrothrombocytopenia-lymphedema-developmental delay-facial dysmorphism-camptodactyly syndrome
• Mandibulofacial dysostosis-macroblepharon-macrostomia syndrome
• Marshall-Smith syndrome
• Microcephaly 4, primary, autosomal recessive
• Midface hypoplasia, hearing impairment, elliptocytosis, and nephrocalcinosis
• Mitochondrial complex 4 deficiency, nuclear type 20
• Mitochondrial complex III deficiency nuclear type 7

• Mucopolysaccharidosis, MPS-III-A to -D
• Neurodevelopmental disorder with dysmorphic facies and variable seizures
• Neurodevelopmental disorder with facial dysmorphism, absent language, and pseudo-pelger-huet anomaly
• Neurodevelopmental disorder with growth retardation, dysmorphic facies, and corpus callosum abnormalities
• Neurodevelopmental disorder with microcephaly, short stature, and speech delay
• Neurodevelopmental disorder with severe motor impairment and absent language
• Neurodevelopmental disorder with spasticity and poor growth
• Neurodevelopmental disorder with spasticity, cataracts, and cerebellar hypoplasia
• Periventricular nodular heterotopia 9
• Pontocerebellar hypoplasia type 7, 8, and 10
• Primrose syndrome
• Severe feeding difficulties-failure to thrive-microcephaly due to ASXL3 deficiency syndrome
• Sialuria
• Skin creases, congenital symmetric circumferential, 2
• Smith-Magenis syndrome
• Spondyloepimetaphyseal dysplasia, Genevieve type
• Spondyloepiphyseal dysplasia, sensorineural hearing loss, impaired intellectual development, and leber congenital amaurosis
• Syndromic X-linked intellectual disability Chudley-Schwartz type
• Syndromic X-linked intellectual disability Nascimento type
• Syndromic X-linked intellectual disability Siderius type
• Syndromic X-linked intellectual disability Snyder type
• Trigonocephaly 1
• Uruguay Faciocardiomusculoskeletal syndrome
• Waardenburg syndrome types 1, 2A, and 3
• Wiedemann-Steiner syndrome
• Zimmermann-Laband syndrome 1, 2, and 3