distal arthrogryposis type 2B1

Distal arthrogryposis type 2B1 is a congenital condition primarily affecting the joints of the hands and feet, leading to reduced range of motion and joint contractures. Although detailed prevalence data is not available, individuals with this condition typically present with joint stiffness and limited movement that may be noticed at birth. Pathogenic variants in the TNNI2 gene are implicated, and this condition follows an autosomal dominant pattern of inheritance. Severity and specific features vary among affected individuals.

While specific characteristic clinical findings are not provided in the available data, distal arthrogryposis type 2B1 generally manifests as decreased mobility in the distal joints such as the hands and feet, leading to stiffness and contractures. These signs are often noted at birth or during early infancy, prompting further evaluation. Not all individuals experience all features, and severity varies considerably.

Distal arthrogryposis type 2B1 is associated with alterations in the TNNI2 gene, which plays a role in muscle contraction. This condition is inherited in an autosomal dominant manner, meaning that inheriting a single copy of the altered gene from an affected parent can be enough to cause the condition. Even within the same family, the severity and specific symptoms can vary considerably, reflecting variable expressivity. Genetic counseling is recommended to help families understand these implications and assess risks for future pregnancies.

Currently, management focuses on supportive care and symptom relief. Although no treatments are specifically approved for distal arthrogryposis type 2B1, care is individualized and often involves a multidisciplinary team that may include orthopedic specialists, physical therapists, and occupational therapists. Genetic counseling is also recommended to assist families with understanding the condition and exploring options for family planning. Patients should discuss treatment options with their healthcare team to determine the most appropriate approach for their situation.

The outlook for individuals with distal arthrogryposis type 2B1 is variable and depends on the severity of joint involvement and response to supportive interventions. With current standards of care, many individuals experience a good quality of life despite lifelong joint stiffness or reduced mobility. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists experienced in managing musculoskeletal conditions and to seek genetic counseling for ongoing guidance and support.