What are the other Names for this Condition? (Also known as/Synonyms)

• AMC, Neurogenic type
• Arthrogryposis Multiplex Congenita, Neurogenic type (AMCN)
• Neurogenic AMC

What is Neurogenic Arthrogryposis Multiplex Congenita? (Definition/Background Information)

• Neurogenic Arthrogryposis Multiplex Congenita, also known as Arthrogryposis Multiplex Congenita, Neurogenic type (or AMCN), refers to the development of multiple joint contractures affecting two or more areas of the body prior to birth
• A contracture occurs when a joint becomes permanently fixed in a bent or straightened position, which can impact the function and range of motion of the joint and lead to muscle atrophy
• Signs and symptoms of Neurogenic Arthrogryposis Multiplex Congenita vary. The condition can affect the upper and lower joints, including the wrists, elbows, fingers, knees, ankles, and hip
• In Neurogenic Arthrogryposis Multiplex Congenita, arthrogryposis occurs as a result of the abnormal development of cells in the spinal cord (anterior horn cells) or brainstem (motor nuclei)
• Neurogenic Arthrogryposis Multiplex Congenita often occurs sporadically (in a person with no family history of the condition), however, families with multiple affected members have also been reported. In most cases, the underlying genetic cause remains unknown

(Source: Neurogenic Arthrogryposis Multiplex Congenita; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Neurogenic Arthrogryposis Multiplex Congenita? (Age and Sex Distribution)

• Neurogenic Arthrogryposis Multiplex Congenita is a rare congenital disorder. The presentation of symptoms may occur at birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Neurogenic Arthrogryposis Multiplex Congenita? (Predisposing Factors)

• A positive family history may be an important risk factor since Neurogenic Arthrogryposis Multiplex Congenita is an inherited condition
• Currently, no other risk factors have been clearly identified for AMCN

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Neurogenic Arthrogryposis Multiplex Congenita? (Etiology)

The cause of Neurogenic Arthrogryposis Multiplex Congenita is poorly understood. To date, no single gene mutation has been found to cause the disorder.

• AMCN often occurs sporadically (in a person with no family history of the condition), however, families with multiple affected members have also been reported
• In these families, genetic linkage studies may give information on how the condition is being passed through the family
• In Neurogenic Arthrogryposis Multiplex Congenita, arthrogryposis occurs as a result of the abnormal development of cells in the spinal cord (anterior horn cells) or brainstem (motor nuclei)

(Source: Neurogenic Arthrogryposis Multiplex Congenita; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

What are the Signs and Symptoms of Neurogenic Arthrogryposis Multiplex Congenita?

Neurogenic Arthrogryposis Multiplex Congenita causes multiple joint contractures affecting two or more areas of the body prior to birth. A contracture occurs when a joint becomes permanently fixed in a bent or straightened position, which can impact the function and range of motion of the joint and lead to muscle atrophy. The contractures may occur alone or along with brain malformations. Learning can be normal to severely impaired depending on the presence of a brain malformation.

The following additional symptoms have been reported in individual cases:

• Scoliosis
• Hip dysplasia
• Hip dislocation
• Differences in facial appearance (e.g., small lower jaw, wide spaced eyes, drooping eyelids, downturned mouth)
• Differences in head shape (e.g., craniosynostosis)
• Rocker bottom feet (feet with a rounded bottom)
• Abnormality of cardiovascular system morphology
• Congenital contracture
• Myopathy

(Source: Neurogenic Arthrogryposis Multiplex Congenita; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Neurogenic Arthrogryposis Multiplex Congenita Diagnosed?

Neurogenic Arthrogryposis Multiplex Congenita is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Neurogenic Arthrogryposis Multiplex Congenita?

The complications of Neurogenic Arthrogryposis Multiplex Congenita may include:

• Walking difficulties
• Heart abnormalities
• Physical deformities
• Brain malformations
• Reduced quality of life

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Neurogenic Arthrogryposis Multiplex Congenita Treated?

The treatment of Neurogenic Arthrogryposis Multiplex Congenita may involve:

• Treatment of arthrogryposis (joint contracture) that involves occupational and physical therapy, well-fitted orthoses (splints and braces), and corrective surgery (if indicated)
• With treatment, most kids can improve their range of motion, muscle strength, and function

(Source: Neurogenic Arthrogryposis Multiplex Congenita; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How can Neurogenic Arthrogryposis Multiplex Congenita be Prevented?

Currently, Neurogenic Arthrogryposis Multiplex Congenita may not be preventable, since it is reportedly a genetic disorder.

• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Neurogenic Arthrogryposis Multiplex Congenita? (Outcomes/Resolutions)

The long-term outlook is good for most people with Neurogenic Arthrogryposis Multiplex Congenita, however, symptoms can vary greatly.

• Life-threatening respiratory problems in early infancy (first year of life) has been rarely reported
• Some infants with AMCN have significant feeding problems, particularly those with brain malformation or a small jaw (micrognathia)
• Children with AMCN affecting lower limbs are often able to walk but may require knee ankle foot orthoses or corrective footwear
• Neurogenic Arthrogryposis Multiplex Congenita does not tend to worsen over time. Muscle strength does not tend to worsen, however, contractures can lead to worsening of function ability
• In the absence of brain malformations, the outlook for cognition and learning is good

(Source: Neurogenic Arthrogryposis Multiplex Congenita; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Additional and Relevant Useful Information for Neurogenic Arthrogryposis Multiplex Congenita:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/