Congenital contractural arachnodactyly

Overview

Congenital Contractural Arachnodactyly (CCA), also known as Beals-Hecht syndrome, is a rare inherited connective tissue disorder characterized by long, slender fingers and toes (arachnodactyly), joint contractures (permanent tightening of muscles or tendons), and abnormalities of the ears and spine. It shares similarities with Marfan syndrome but is considered a distinct genetic condition. Most cases are present at birth and may involve skeletal, muscular, and, in some cases, cardiovascular features.

Causes

CCA is caused by mutations in the FBN2 gene, which provides instructions for making fibrillin-2, a protein essential for the formation of elastic fibers in connective tissue. The condition is inherited in an autosomal dominant manner, meaning only one copy of the mutated gene is sufficient to cause the disorder. Most individuals inherit the mutation from an affected parent, but de novo (new) mutations can also occur.

Symptoms

The severity and presentation of symptoms can vary, but hallmark features of CCA include:

• Arachnodactyly: Long, slender fingers and toes

• Joint contractures: Particularly affecting elbows, knees, and fingers at birth

• Cramped or flexed posture: Often seen in newborns

• Scoliosis: Abnormal curvature of the spine, which may progress with age

• Muscle underdevelopment: Muscle tone may be reduced, especially in early life

• Crumbled or "crumpled" ears: A unique physical feature that helps differentiate CCA from similar syndromes

• Pectus excavatum or carinatum: Sunken or protruding chest

• Mild facial differences: Including high-arched palate or long narrow face (in some cases)

• Occasional heart problems: Such as aortic root dilation or mitral valve prolapse, although less common than in Marfan syndrome

Diagnosis

Diagnosis of CCA is based on clinical findings, family history, and genetic testing. Diagnostic steps include:

• Physical examination: To assess joint contractures, skeletal abnormalities, and characteristic features

• Family history review: To check for inheritance patterns

• Genetic testing: Identification of mutations in the FBN2 gene confirms the diagnosis

• Echocardiogram: To monitor for cardiovascular abnormalities, although these are less severe than in Marfan syndrome

• X-rays and spine imaging: To evaluate scoliosis and other bone deformities

• Differential diagnosis: To distinguish from Marfan syndrome and other connective tissue disorders

Treatment

There is no cure for CCA, so treatment focuses on managing symptoms, improving mobility, and monitoring for complications. A multidisciplinary team approach is often required. Treatment options include:

• Physical and occupational therapy: To maintain joint mobility and prevent worsening contractures

• Orthopedic interventions: Bracing or surgery for scoliosis or severe joint deformities

• Cardiac monitoring: Regular echocardiograms to detect any heart valve or aortic abnormalities

• Assistive devices: Braces or orthotics to support ambulation and posture

• Surgical correction: For severe joint contractures or progressive spinal deformities

• Genetic counseling: For affected families to understand inheritance risks and options

Prognosis

The prognosis for individuals with Congenital Contractural Arachnodactyly is generally good, especially when managed with early interventions and supportive care. Most children show improvement in joint mobility over time, and intellectual development is typically normal. Scoliosis and joint contractures may require ongoing management, but life expectancy is usually not affected. With appropriate therapy and monitoring, individuals with CCA can lead active and productive lives.