Arthrogryposis, which is also known by the name of Arthrogryposis Multiplex Congenital, is a pathological condition characterized by multiple joint contractures and muscle weakness throughout the body at the time of the birth of the child. Arthrogryposis is a symptom more than a condition and hence an underlying cause for it has to be identified.
Amyoplasia is the most common form of Arthrogryposis which is characterized by contractures of the hands, wrists, elbows, shoulders, hips, feet and knees, although the severe form of Arthrogryposis can cause contractures in every joint in the body, including the jaw and the spinal cord.
There is no single cause for the development of Arthrogryposis, although studies suggest that fetal akinesia plays a vital role in a child developing Arthrogryposis. During fetal development it is normal for the fetus to have normal joint movement and development during the early phase of pregnancy. Problems occur when there is a lack of fetal movement during the development phase of the fetus which results in extra connective tissue to develop causing an immobile and stiff joint which ultimately results in the development of Arthrogryposis. The longer is the duration of immobility of the joint, the severe will be Arthrogryposis.
Is Arthrogryposis Genetic?
The answer to this question is, Yes, Arthrogryposis is a congenital disorder. Studies have proven that Arthrogryposis can be caused by mutations in at least two genes which are TPM2 and MYBPC1. These genes are active in the muscle cells and interact with the muscle proteins to facilitate muscle contraction.
However, these studies do not gives a clear reason as to how mutations in the above mentioned genes can result in the development of joint contractures which are the characteristic features of Arthrogryposis. Researchers however believe that these contractures are related to problems with muscle contraction which limit the mobility of the joint and result in contractures seen in a condition like Arthrogryposis.
Arthrogryposis is inherited in an autosomal dominant pattern meaning that one copy of the defective gene from either parent is good enough for the development of Arthrogryposis. In most of the cases, a child with this condition will have a parent or a direct relative or sibling with Arthrogryposis.
- National Organization for Rare Disorders (NORD). (2022). Arthrogryposis Multiplex Congenita https://rarediseases.org/rare-diseases/arthrogryposis-multiplex-congenita/
- U.S. National Library of Medicine. (2022). Genetics of Arthrogryposis Multiplex Congenita https://pubmed.ncbi.nlm.nih.gov/34492343/