Fairbanks disease
Encyclopedia
Fairbanks disease or multiple epiphyseal dysplasia (MED) is a rare genetic disorder
(dominant form—1 in 10,000 births) which affects the growing ends of bones
. Bones usually elongate by a process that involves the depositing of cartilage
at the ends of the bones, called ossification
. This cartilage then mineralize
s and hardens to become bone. In MED, this process is defective.
form. However, there is also an autosomal recessive form.
Associated genes include COL9A2
, COL9A3
, COMP
, and MATR3
.
Types include:
and fatigue after exercising. Their x-ray
s show small and irregular ossifications centers, most apparent in the hips and knee
s. A waddling gait
may develop. The spine
is normal but may have a few irregularities. By adulthood, people with MED are of short stature or in the low range of normal and have short limbs relative to their trunk. Frequently, movement becomes limited at the major joints, especially at the elbows. However, loose knee and finger joints can occur. Signs of osteoarthritis
usually begin in early adulthood.
Children with recessive MED also experience joint pain, particularly of the hips and knees, but they also commonly have deformities of the hands, feet, knees, and/or vertebral column (like scoliosis
). Approximately 50% of affected children have abnormal findings at birth (i.e. club foot
, cleft palate, inward curving fingers due to underdeveloped bones, or rarely, ear swelling). Height is within the normal range prior to puberty. As adults, people with recessive MED are only slightly more diminished in stature but still within the normal range. Functional disabilities of the joints are mild or absent.
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....
(dominant form—1 in 10,000 births) which affects the growing ends of bones
Epiphyseal plate
The epiphyseal plate is a hyaline cartilage plate in the metaphysis at each end of a long bone...
. Bones usually elongate by a process that involves the depositing of cartilage
Cartilage
Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...
at the ends of the bones, called ossification
Ossification
Ossification is the process of laying down new bone material by cells called osteoblasts. It is synonymous with bone tissue formation...
. This cartilage then mineralize
Mineralization
Mineralization may refer to:* Mineralization , the process through which an organic substance becomes impregnated by inorganic substances...
s and hardens to become bone. In MED, this process is defective.
Inheritance
Multiple epiphyseal dysplasia (MED) encompasses a spectrum of skeletal disorders, most of which are inherited in an autosomal dominantDominance relationship
Dominance in genetics is a relationship between two variant forms of a single gene, in which one allele masks the effect of the other in influencing some trait. In the simplest case, if a gene exists in two allelic forms , three combinations of alleles are possible: AA, AB, and BB...
form. However, there is also an autosomal recessive form.
Associated genes include COL9A2
COL9A2
Collagen alpha-2 chain is a protein that in humans is encoded by the COL9A2 gene.-External links:* -Further reading:...
, COL9A3
COL9A3
Collagen alpha-3 chain is a protein that in humans is encoded by the COL9A3 gene.-External links:* -Further reading:...
, COMP
Comp
Comp may refer to:In music:*Accompaniment, especially in jazz *Compilation album*Comp In business and finance:*Comparable company analysis*Comparables, in real estate*Same Store Sales...
, and MATR3
MATR3
Matrin-3 is a protein that in humans is encoded by the MATR3 gene.-Further reading:...
.
Types include:
| Type | OMIM | Gene |
|---|---|---|
| EDM1 | COMP Comp Comp may refer to:In music:*Accompaniment, especially in jazz *Compilation album*Comp In business and finance:*Comparable company analysis*Comparables, in real estate*Same Store Sales... |
|
| EDM2 | COL9A2 COL9A2 Collagen alpha-2 chain is a protein that in humans is encoded by the COL9A2 gene.-External links:* -Further reading:... |
|
| EDM3 | COL9A3 COL9A3 Collagen alpha-3 chain is a protein that in humans is encoded by the COL9A3 gene.-External links:* -Further reading:... |
|
| EDM4 | DTDST | |
| EDM5 | MATN3 MATN3 Matrilin-3 is a protein that in humans is encoded by the MATN3 gene.-External links:* -Further reading:... |
|
| EDM6 | COL9A1 COL9A1 Collagen alpha-1 chain is a protein that in humans is encoded by the COL9A1 gene.-External Links:* * -Further reading:... |
Presentation
Children with autosomal dominant MED experience joint painArthralgia
Arthralgia literally means joint pain; it is a symptom of injury, infection, illnesses or an allergic reaction to medication....
and fatigue after exercising. Their x-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s show small and irregular ossifications centers, most apparent in the hips and knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
s. A waddling gait
Gait
Gait is the pattern of movement of the limbs of animals, including humans, during locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on speed, terrain, the need to maneuver, and energetic efficiency...
may develop. The spine
Vertebral column
In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...
is normal but may have a few irregularities. By adulthood, people with MED are of short stature or in the low range of normal and have short limbs relative to their trunk. Frequently, movement becomes limited at the major joints, especially at the elbows. However, loose knee and finger joints can occur. Signs of osteoarthritis
Osteoarthritis
Osteoarthritis also known as degenerative arthritis or degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. Symptoms may include joint pain, tenderness, stiffness, locking, and sometimes an effusion...
usually begin in early adulthood.
Children with recessive MED also experience joint pain, particularly of the hips and knees, but they also commonly have deformities of the hands, feet, knees, and/or vertebral column (like scoliosis
Scoliosis
Scoliosis is a medical condition in which a person's spine is curved from side to side. Although it is a complex three-dimensional deformity, on an X-ray, viewed from the rear, the spine of an individual with scoliosis may look more like an "S" or a "C" than a straight line...
). Approximately 50% of affected children have abnormal findings at birth (i.e. club foot
Club foot
A club foot, or congenital talipes equinovarus , is a congenital deformity involving one foot or both. The affected foot appears rotated internally at the ankle. TEV is classified into 2 groups: Postural TEV or Structural TEV....
, cleft palate, inward curving fingers due to underdeveloped bones, or rarely, ear swelling). Height is within the normal range prior to puberty. As adults, people with recessive MED are only slightly more diminished in stature but still within the normal range. Functional disabilities of the joints are mild or absent.