Congenital contractural arachnodactyly

A rare genetic disorder affecting connective tissue

Congenital contractural arachnodactyly (CCA), also known as Beals syndrome, is a rare genetic disorder that affects the connective tissue in the body. It is characterized by arachnodactyly, which refers to abnormally long and slender fingers and toes, and contractures, which are permanent shortening of muscles or tendons around joints. This condition is similar to Marfan syndrome, but it has distinct features and is caused by mutations in a different gene.

Genetics

Congenital contractural arachnodactyly is caused by mutations in the FBN2 gene, which provides instructions for making a protein called fibrillin-2. Fibrillin-2 is an essential component of the extracellular matrix, which provides structural support to tissues and organs. Mutations in the FBN2 gene lead to the production of an abnormal fibrillin-2 protein, disrupting the normal function of connective tissue.

CCA is inherited in an autosomal dominant pattern, meaning that a single copy of the altered gene in each cell is sufficient to cause the disorder. This means that an affected individual has a 50% chance of passing the mutation to their offspring.

Clinical Features

Individuals with congenital contractural arachnodactyly typically present with a range of clinical features, including:

• Arachnodactyly: Long, slender fingers and toes.
• Contractures: Permanent shortening of muscles or tendons, particularly affecting the elbows, knees, and fingers.
• Kyphoscoliosis: A combination of kyphosis (outward curvature of the spine) and scoliosis (sideways curvature of the spine).
• Crumpled ears: The outer ear may appear crumpled or folded.
• Muscle hypoplasia: Underdevelopment of muscles, leading to reduced muscle mass and strength.
• Joint laxity: Increased flexibility of the joints, which may lead to joint instability.

Diagnosis

The diagnosis of congenital contractural arachnodactyly is based on clinical evaluation, family history, and genetic testing. A healthcare provider may suspect CCA based on the characteristic physical features and may confirm the diagnosis through genetic testing to identify mutations in the FBN2 gene.

Management

There is no cure for congenital contractural arachnodactyly, but management focuses on alleviating symptoms and improving quality of life. Treatment options may include:

• Physical therapy: To improve joint mobility and muscle strength.
• Orthopedic interventions: Such as braces or surgery to correct joint contractures or spinal deformities.
• Regular monitoring: To assess and manage any complications, such as scoliosis or joint problems.

Prognosis

The prognosis for individuals with congenital contractural arachnodactyly varies depending on the severity of the condition and the presence of any complications. With appropriate management, many individuals can lead relatively normal lives, although they may require ongoing medical care and support.

Related pages

• Marfan syndrome
• Connective tissue disorder
• Genetic disorder