Arthrochalasia Ehlers-Danlos syndrome

Alternate names

Arthrochalasis multiplex congenita; Ehlers-Danlos syndrome type 7A (formerly); EDS7A (formerly); Arthrochalasia EDS; aEDS; Ehlers-Danlos syndrome, arthrochalasia type

Definition

Arthrochalasia Ehlers-Danlos syndrome (aEDS) is an inherited connective tissue disorder that is caused by defects in a protein called collagen.

Cause

• Arthrochalasia EDS (aEDS) is caused by changes (mutations) in the COL1A1 gene or the COL1A2 gene.
• These genes provide instructions for making a component of type I collagen.
• Collagen is a protein that provides structure and strength to connective tissues throughout the body.
• Type I collagen, specifically, is the most abundant form of collagen in the human body.

Gene mutations

• Mutations in COL1A1 or COL1A2 lead to structural abnormalities in type I collagen molecules.
• This weakens tissues that are rich in type I collagen, such as the skin, bones, and tendons and causes the many signs and symptoms associated with aEDS.

Inheritance

Autosomal dominant pattern, a 50/50 chance.

• Arthrochalasia EDS is inherited in an autosomal dominant manner.
• This means that to be affected, a person only needs a change (mutation) in one copy of the responsible gene in each cell.
• In some cases, an affected person inherits the mutation from an affected parent.
• Other cases may result from new (de novo) mutations in the gene.
• These cases occur in people with no history of the disorder in their family.
• A person with EDS, arthrochalasia type has a 50% chance with each pregnancy of passing along the altered gene to his or her child.

Signs and symptoms

The signs and symptoms of arthrochalasia Ehlers-Danlos syndrome (EDS) vary but may include:

• Severe joint hypermobility which may lead to recurrent joint dislocations and subluxations (partial dislocation)
• Congenital hip dislocation
• Fragile, hyperextensible skin with easy bruising
• Hypotonia
• Delayed motor development
• Kyphoscoliosis (kyphosis and scoliosis)
• Mild osteopenia (low bone density)
• Characteristic facial features (i.e. wide-spaced eyes, epicanthal folds, large anterior fontanelle and micrognathia)

Clinical presentation

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed.

80%-99% of people have these symptoms

• Abnormality of subcutaneous fat tissue(Abnormality of fatty tissue below the skin)
• Aphasia(Difficulty finding words)
• Avascular necrosis of the capital femoral epiphysis
• Coxa valga
• Coxa vara
• Dysphasia
• Echolalia(Echoing another person's speech)
• Hip dislocation(Dislocated hips)
• Hip dysplasia
• Hyperextensible skin(Hyperelastic skin)
• Joint hyperflexibility(Joints move beyond expected range of motion)
• Joint stiffness(Stiff joint)
• Muscle flaccidity
• Muscular hypotonia(Low or weak muscle tone)
• Mutism(Inability to speak)
• Scarring
• Severe short stature(Dwarfism)
• Thin skin

30%-79% of people have these symptoms

• Depressed nasal bridge(Depressed bridge of nose)
• Epicanthus(Eye folds)
• Hypertelorism(Wide-set eyes)
• Micrognathia(Little lower jaw)
• Retrognathia(Receding chin)
• Scoliosis

5%-29% of people have these symptoms

• Femoral hernia
• Inguinal hernia

Diagnosis

• A diagnosis of arthrochalasia EDS is typically based on the presence of characteristic signs and symptoms.
• Genetic testing for a change (mutation) in COL1A1 or COL1A2 can then be ordered to confirm the diagnosis.
• Collagen typing performed on a skin biopsy may be recommended if genetic testing is inconclusive.
• Collagen is a tough, fiber-like protein that makes up about a third of body protein.
• It is part of the structure of tendons, bones, and connective tissues.
• People with aEDS have abnormalities in type I collagen.

Treatment

• The treatment of arthrochalasia Ehlers-Danlos syndrome (aEDS) is focused on preventing serious complications and relieving associated signs and symptoms.
• For example, physical therapy may be recommended in children with severe hypotonia and delayed motor development. This treatment can also help improve joint stability.
• Assistive devices such as braces, wheelchairs, or scooters may be necessary depending on the severity of joint instability.
• Congenital hip dislocation and kyphoscoliosis (kyphosis and scoliosis) may require surgery.
• Because aEDS is associated with fragile skin, affected people, especially children, may need to wear protective bandages or pads over exposed areas, such as the knees, shins, and forehead.

NIH genetic and rare disease info

• NIH info on Arthrochalasia Ehlers-Danlos syndrome

Arthrochalasia Ehlers-Danlos syndrome is a rare disease.