Rare diseases · Sign or symptom
Genu valgum
Knock knees
HP:0002857
What it means
The legs angle inward, such that the knees are close together and the ankles far apart.
Rare diseases that can present with this98
Very common80–99%
21- Aromatase deficiency
- Cataract-growth hormone deficiency-sensory neuropathy-sensorineural hearing loss-skeletal dysplasia syndrome
- CHST3-related skeletal dysplasia
- Difference of sex development-intellectual disability syndrome
- Dysmorphism-pectus carinatum-joint laxity syndrome
- Ellis-Van Creveld syndrome
- Facial dysmorphism-shawl scrotum-joint laxity syndrome
- Mesomelic dysplasia, Nievergelt type
- Microtriplication 11q24.1 syndrome
- Mucopolysaccharidosis type 4
- Multiple epiphyseal dysplasia, Lowry type
- Multiple epiphyseal dysplasia-macrocephaly-facial dysmorphism syndrome
- Non-eruption of teeth-maxillary hypoplasia-genu valgum syndrome
- Pseudoleprechaunism syndrome, Patterson type
- Pyle disease
- Rhizomelic dysplasia, Patterson-Lowry type
- Schwartz-Jampel syndrome
- SHOX-related short stature
- Spondyloepimetaphyseal dysplasia, Irapa type
- Thoracomelic dysplasia
- X-linked intellectual disability, Stevenson type
Common30–79%
44- Acrocraniofacial dysostosis
- Albers-Schönberg osteopetrosis
- Atelosteogenesis type II
- Beta-mercaptolactate cysteine disulfiduria
- Beta-thalassemia major
- Brachytelephalangy-dysmorphism-Kallmann syndrome
- Cardiac-valvular Ehlers-Danlos syndrome
- Carpenter syndrome
- Cohen syndrome
- Congenital patella dislocation
- Diastrophic dysplasia
- Distal deletion 15q syndrome
- Distal duplication 17q syndrome
- Dysplasia epiphysealis hemimelica
- Dysspondyloenchondromatosis
- Homocystinuria due to cystathionine beta-synthase deficiency
- Hypogonadotropic hypogonadism-severe microcephaly-sensorineural hearing loss-dysmorphism syndrome
- Isolated fibular hemimelia
- Isolated megalencephaly
- Léri-Weill dyschondrosteosis
- Marshall syndrome
- Monosomy X syndrome
- Mosaic monosomy X syndrome
- Mowat-Wilson syndrome
- Mucolipidosis type III
- Mucopolysaccharidosis type 3
- Mucopolysaccharidosis type 6
- Multiple epiphyseal dysplasia type 4
- Multiple epiphyseal dysplasia type 5
- Neurofibromatosis type 1
- Osteogenesis imperfecta
- Progressive spondyloepimetaphyseal dysplasia-short stature-short fourth metatarsals-intellectual disability syndrome
- Prolidase deficiency
- SPONASTRIME dysplasia
- Spondyloepimetaphyseal dysplasia with joint laxity, leptodactylic type
- Spondyloepiphyseal dysplasia congenita
- Spondylometaphyseal dysplasia, 'corner fracture' type
- Spondylometaphyseal dysplasia, Schmidt type
- Stickler syndrome
- Stüve-Wiedemann syndrome
- Turner syndrome
- Turner syndrome due to structural X chromosome anomalies
- Williams syndrome
- X-linked hypophosphatemia
Sometimes5–29%
14- Alpha-mannosidosis, infantile form
- Autosomal recessive spastic paraplegia type 20
- Camurati-Engelmann disease
- Cardiofaciocutaneous syndrome
- Cleidocranial dysplasia
- COG5-CDG
- Cortical dysgenesis with pontocerebellar hypoplasia due to TUBB3 mutation
- Dyggve-Melchior-Clausen disease
and 6 more in this range
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: Genu valga · Genu valgus · Genua valga · Knee joint valgus deformity
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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.