Background:
Congenital contractural arachnodactyly (CCA) has only recently been described as a syndrome distinct from Marfan syndrome. Both conditions are heritable disorders of the connective tissue. The two are clinically related but result from mutations in different genes.

What are the clinical features of CCA?
CCA patients share skeletal features with Marfan syndrome (tall and slender with arm span exceeding height), but lack the ocular and usually the life threatening cardiovascular complications associated with Marfan syndrome. CCA patients may demonstrate the following skeletal features:

• congenital contractures (shortening of muscle tissue, rendering the muscle highly resistant to passive stretching) of multiple joints (ex. fingers, elbows, knees, toes and hips) Delay in motor development often occurs as a result of contractures.
• crumpled appearance to the upper helix of the external ear
• arachnodactyly -long, slender fingers and toes
• scoliosis - lateral curvature of vertebral column
• kyphoscoliosis, a backward and lateral curvature of vertebral column at birth or early childhood
• osteopenia - reduced bone mass
• dolichostenomelia - long, narrow body habitus
• pectus deformities - concave chest (pectus excavatum) or pigeon chest  (pectus carinatum)
• muscular hypoplasia (underdevelopment of muscles - usually calves)
• facial abnormalities, such as micrognathia (unusually small jaws) and highly arched palate

Will CCA patients have the cardiovascular complications associated with Marfan syndrome?
Although it was initially believed that CCA patients would not have an aortic root dilatation, recently it has been shown that some do. However, it has not yet been determined if the aortic root dilatation observed in these patients will progress to an aortic dissection or rupture, as is the case with Marfan Syndrome. Therefore it is still recommended that CCA patients still have their heart regularly monitored by echocardiogram.

What is the inheritance pattern of CCA?
CCA is an autosomal dominant condition caused by a mutation in the gene for the fibrillin-2 protein FBN2. The FBN2 gene has been mapped to chromosome 5q 23-31. Many individuals diagnosed with CCA have an affected parent, however the disease could result from a new gene mutation. Affected individuals have a 50% chance of passing the abnormal FBN2 allele to each offspring.

How common is CCA?
Although the exact incidence of CCA is not known, the condition occurs rarely in comparison to Marfan syndrome. The difficulty in determining the prevalence of CCA originates from the frequent overlap of clinical features between CCA and Marfan syndrome, making it difficult to distinguish between the two.

What is the current research being done with CCA?
Current studies are being done to further characterize the FBN-2 protein in order to better understand the molecular basis of CCA and its distinction from Marfan syndrome.

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