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Disease Profile

Fibular hemimelia

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

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ICD-10

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Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

Congenital longitudinal deficiency of the fibula; Fibular longitudinal meromelia

Categories

Congenital and Genetic Diseases; Musculoskeletal Diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
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Orpha Number: 93323

Definition
Fibular hemimelia is a congenital longitudinal limb deficiency characterized by complete or partial absence of the fibula bone.

Epidemiology
Prevalence is estimated at 1 in 50,000. A slight male preponderance has been reported in some studies, whereas other reports describe an equal sex distribution.

Clinical description
Unilateral involvement occurs in two-thirds of cases, with the right fibula being affected more often than the left. Agenesis of both fibulae is rare. Fibular hemimelia may vary from partial absence of the fibula (10% of cases) with relatively normal-appearing limbs, to absence of the fibula with marked shortening of the femur, curved tibia, bowing of the leg, knee joint and ankle instability and significant soft tissue deficiency. The major functional deficiency results from leg length discrepancy in unilateral cases or asymmetrical dwarfism in bilateral cases. The foot is generally in an equinovalgus position. As there is limited growing potential within the affected bone, the extent of the deformity tends to increase with growth. Occasionally, fibular hemimelia is associated with congenital shortening of the femur (femur-fibula-ulna complex; see this term). Other skeletal anomalies (craniosynostosis, syndactyly, brachydactyly, oligodactyly and ectrodactyly) may also be present. Fibular hemimelia is also found in several generalized skeletal dysplasias and dysostoses. Rarely, fibular hemimelia is associated with nonskeletal malformations (eye abnormalities such as anterior chamber anomalies or anophthalmia, cardiac anomalies, renal dysplasia, thrombocytopenia, thoracoabdominal schisis, spina bifida and, rarely, intellectual deficit). Fibular hemimelia can be present in some chromosome anomalies.

Etiology
The etiology is unclear. The deformity is probably due to disruptions during the critical period of embryonic limb development, between 4th and 7th week of gestation. Vascular dysgenesis, viral infections, trauma and environmental influences have been suggested as possible causes.

Diagnostic methods
Diagnosis is based on clinical examination and X-rays.

Differential diagnosis
Differential diagnoses include amniotic band syndrome, thalidomide embryopathy and several skeletal dysplasias and dysostoses with asymmetrical involvement of the lower limbs such as femoral-facial syndrome (see these terms).

Antenatal diagnosis
Prenatal diagnosis of fibular hemimelia has been reported.

Genetic counseling
Most cases are sporadic. A family history has been reported in a small percentage of cases with an autosomal dominant pattern of inheritance and incomplete penetrance.

Management and treatment
Management requires a multidisciplinary approach (genetic counselors, perinatologists and pediatric orthopedic surgeons). Orthopedic treatment aims at correcting the leg length discrepancy, and, in bilateral cases, correcting the asymmetrical dwarfism. In less severe cases with minimal hypoplasia of the fibula and only mild limb length discrepancy, special shoes and/or accommodative insoles may be used to equalize limb length. In some mild cases, epiphysiodesis on the contralateral (normal) side is also an option. In moderate limb length inequality, limb lengthening is an option but it carries the risk of requiring multiple reconstructive procedures and complications. Rarely, for cases of severe limb length discrepancy or complete absence of the fibula when the foot is nonfunctional, amputation with prosthetic fitting in early childhood may be considered.

Prognosis
Fibular deficiency is usually a benign condition, although in severe cases it can be debilitating. Acceptable functional results may be achieved by surgery. In case of syndromic presentation, prognosis depends on the nature of the associated anomalies.

Visit the Orphanet disease page for more resources.

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Difficulty walking
Difficulty in walking
0002355
30%-79% of people have these symptoms
Disproportionate prominence of the femoral medial condyle
0006437
Genu valgum
Knock knees
0002857
Limb undergrowth
limb shortening
Short limb
Short limbs

[ more ]

0009826
Lower limb asymmetry
Left and right leg differ in length or width
0100559
Short tibia
Short shinbone
Short skankbone

[ more ]

0005736
Talipes equinovarus
Club feet
Club foot
Clubfeet
Clubfoot

[ more ]

0001762
Tibial bowing
Bowed shankbone
Bowed shinbone

[ more ]

0002982
5%-29% of people have these symptoms
Abnormal bone ossification
0011849
Arthralgia of the hip
Hip joint pain
0003365
Decreased hip abduction
0003184
Fibular hypoplasia
Short calf bone
0003038
Finger syndactyly
0006101
Hip subluxation
Partial hip dislocation
0030043
Impairment of activities of daily living
0031058
Increased laxity of ankles
0006460
Joint laxity
Joint instability
Lax joints
Loose-jointedness
Loosejointedness

[ more ]

0001388
Joint stiffness
Stiff joint
Stiff joints

[ more ]

0001387
Knee joint hypermobility
Knee joint over-flexibility
0045086
Limited knee flexion/extension
0005085
Pain
0012531
Proximal femoral focal deficiency
0030772
Short femur
Short thighbone
0003097
Short toe
Short toes
Stubby toes

[ more ]

0001831
Structural foot deformity
0010219
Talipes equinovalgus
0001772
Toe syndactyly
Fused toes
Webbed toes

[ more ]

0001770
1%-4% of people have these symptoms
Abnormal anterior chamber morphology
0000593
Abnormal heart morphology
Abnormality of the heart
Abnormally shaped heart
Heart defect

[ more ]

0001627
Abnormal morphology of ulna
0040071
Anophthalmia
Absence of eyeballs
Failure of development of eyeball
Missing eyeball
No eyeball

[ more ]

0000528
Craniosynostosis
0001363
Ectrodactyly
Cleft hand
Lobster claw hand

[ more ]

0100257
Fibular aplasia
Absent calf bone
0002990
Foot oligodactyly
Missing toes
0001849
Hypoplastic acetabulae
0003274
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

0001249
Renal dysplasia
0000110
Spina bifida
0002414
Thoracoabdominal wall defect
0100656
Thrombocytopenia
Low platelet count
0001873

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.