Congenital contractural arachnodactyly

Congenital contractural arachnodactyly (CCA) is caused by mutations in the FBN2 gene. The FBN2 gene provides instructions for producing the fibrillin-2 protein. Fibrillin-2 binds to other proteins and molecules to form threadlike filaments called microfibrils. Microfibrils become part of the fibers that provide strength and flexibility to connective tissue. Additionally, microfibrils hold molecules called growth factors and release them at the appropriate time to control the growth and repair of tissues and organs throughout the body. A mutation in the FBN2 gene can reduce the amount and/or quality of fibrillin-2 that is available to form microfibrils. As a result, decreased microfibril formation weakens the elastic fibers and allows growth factors to be released inappropriately, causing tall stature, deformities of the fingers and toes, and other characteristic features of CCA.

This condition is inherited in an autosomal dominant pattern, which means one copy of the mutated gene in each cell is enough to cause the disorder. In some cases, an affected person inherits the mutation from an affected parent. Other cases result from new ( de novo ) mutations in the gene and occur in people with no history of the disorder in their family.

Because many factors influence a person's height, we cannot comment on how tall you will be. We searched the medical literature to learn more about how a person's height might be affected by CCA, and we found that limited information exist regarding this topic. One review article including the clinical findings of 32 individuals with CCA states that patients tend to be tall (>90th percentile) from birth onward, in the absence of curvature of the spine (scoliosis). However, it is important to note that symptoms vary from person to person; therefore, not all affected people are taller than other people in their family.

Congenital contractural arachnodactyly (CCA) is a genetic disorder that is characterized by tall height; skinny, long limbs; long, skinny fingers and toes (arachnodactyly); multiple joint deformities present at birth (congenital contractures), usually of the elbows, knees, hips, fingers and ankles; "crumpled"-looking ears; and curvature of the spine (kyphoscoliosis). Enlargement (dilation) of the aorta and other features might also be present in some affected people. CCA is caused by mutations in a gene called FBN2 gene and is inherited in an autosomal dominant pattern. CCA shares similiar signs and symptoms to Marfan syndrome; however, Marfan syndrome is not caused by mutations in the FBN2 gene. Treatment includes physical therapy or surgery for joint contractures, bracing and/or surgery for kyphoscoliosis, and standard management of aortic root dilation.

Physical therapy for joint contractures helps increase joint mobility and improve the effects of muscle hypoplasia (usually in the calf muscles). In severe cases, surgery may be needed. Since the kyphosis/scoliosis tends to be progressive, bracing and/or surgical correction is often needed. Consultation with an orthopedist is encouraged. Other symptoms, if present, should be addressed as they arise. Regular physician visits should be scheduled to monitor symptom progression and development.