arthrogryposis multiplex congenita 3, myogenic type

Arthrogryposis multiplex congenita 3, myogenic type is a congenital condition primarily affecting the muscles and joints, leading to multiple joint contractures present at birth. It is genetically linked to variants in the SYNE1 gene, which plays an important role in muscle structure and function. The condition typically manifests in early life, with affected individuals showing signs such as reduced fetal movement and delayed motor milestones. Precise prevalence estimates are not established, and the overall presentation can vary significantly between individuals.

The clinical presentation of arthrogryposis multiplex congenita 3, myogenic type is marked by congenital joint contractures and significant delays in gross motor development. Characteristic features include decreased fetal movement, arthrogryposis, and bilateral foot deformities such as talipes equinovarus, along with delayed ability to walk. Other consistently observed signs are hypotonia, characteristic muscle weakness, hyporeflexia, and specific findings like strabismus, hypermetropia, and an adducted thumb. In some individuals, additional features such as scoliosis, kyphoscoliosis, restrictive ventilatory defects, and variability in muscle fiber diameter may also be noted. Not all individuals experience all features, and severity varies considerably.

Arthrogryposis multiplex congenita 3, myogenic type is associated with pathogenic variants in the SYNE1 gene. SYNE1 encodes a protein that is crucial for maintaining the structure of the nuclear envelope in muscle cells, and its disruption can impair normal muscle development and function. The condition is inherited in an autosomal recessive pattern, which means that an affected individual has inherited a mutated copy of the gene from each parent. Families of affected individuals may benefit from genetic counseling to understand recurrence risks and carrier implications.

Currently, management focuses on supportive care and symptom management since there are no specific treatments approved for arthrogryposis multiplex congenita 3, myogenic type. Treatment is highly individualized and typically involves a multidisciplinary team to address the various manifestations of the condition. Supportive interventions include physical therapy, occupational therapy, and other rehabilitative services aimed at maximizing motor function. Regular surveillance is an essential part of long-term care, helping to detect potential complications early. In addition, genetic counseling is recommended to help families understand the inheritance pattern and explore available support resources.

The overall prognosis for individuals with arthrogryposis multiplex congenita 3, myogenic type is highly variable, with outcomes depending on the severity of symptoms, age at diagnosis, and access to specialized care. With current standards of care, many individuals can experience meaningful improvements in quality of life, and some may continue to develop skills over time despite early delays. That outcomes described in medical literature continue to evolve as standards of care improve. Families are encouraged to connect with specialists who are familiar with this condition as well as genetic counselors to discuss ongoing management and future planning.