arthrogryposis, distal, type 1A

Arthrogryposis, distal, type 1A is a condition affecting the musculoskeletal system that primarily involves joint contractures in the distal parts of the limbs. It is associated with pathogenic variants in the TPM2 gene, which plays a role in muscle contraction. The condition follows an autosomal dominant pattern of inheritance and typically presents during early life. Although precise prevalence data are not available, the clinical expression varies among affected individuals.

Individuals with arthrogryposis, distal, type 1A often exhibit joint contractures that affect the hands and feet. Common clinical features include overlapping fingers, absent distal interphalangeal creases, ulnar deviation of the hand or fingers, talipes equinovarus (clubfoot), rocker bottom foot, and camptodactyly. Not all individuals experience every feature, and the severity of joint involvement can differ considerably from one person to another.

The condition is linked to changes in the TPM2 gene, which is important for the proper function of muscle fibers. These genetic alterations disrupt normal muscle contraction, leading to the joint contractures seen in this condition. It is inherited in an autosomal dominant pattern, meaning that a single altered copy of the TPM2 gene can be sufficient to cause the condition. However, even within families, the severity and specific manifestations can vary considerably (variable expressivity).

Currently, management focuses on supportive care and symptom management rather than on treatments specifically approved for arthrogryposis, distal, type 1A. Therapeutic approaches are tailored to the individual and typically involve a multidisciplinary team that may include physical and occupational therapists, as well as orthopedic specialists to address joint function and mobility. Genetic counseling is also recommended to help families understand the inheritance pattern and to discuss family planning options. Patients should discuss treatment options with their healthcare team to determine the most appropriate approach for their specific situation.

The course of arthrogryposis, distal, type 1A is highly variable, with some individuals experiencing mild limitations while others may have more pronounced joint involvement. With current standards of care, many individuals are able to achieve and maintain a good quality of life, and outcomes described in medical literature continue to evolve as standards of care improve. It is important to recognize that severity and symptoms vary widely between individuals, and ongoing monitoring by a multidisciplinary team can help address emerging challenges. Connecting with a genetic counselor or a specialist familiar with the condition can provide additional support and guidance.