Congenital Contractural Arachnodactyly

Definition

An autosomal dominant connective tissue disorder caused by FBN2 mutations, also called Beals syndrome. It resembles Marfan syndrome but adds congenital contractures and crumpled ears.

Aetiology

  • FBN2 mutations on chromosome 5q23
  • Fibrillin 2 is a microfibril protein related to fibrillin 1 of Marfan syndrome
  • Variable expression within families

Clinical Features

  • Crumpled upper helix of the ear
  • Arachnodactyly and camptodactyly
  • Flexion contractures of elbows, knees and hips at birth
  • Contractures improve with age
  • Kyphoscoliosis, which can be early onset and progressive
  • Marfanoid habitus with long slender limbs
  • Adducted thumbs and clubfoot in some
  • Aortic root dilatation and lens dislocation less frequent than in Marfan syndrome
  • Calf muscle hypoplasia

Investigations

  • Echocardiogram for aortic root and mitral valve
  • Ophthalmology review
  • Spinal radiographs for scoliosis
  • FBN2 genetic testing
  • Hand radiographs show long slender metacarpals and phalanges

Differential Diagnosis

Management

  • Physiotherapy and stretching. First line for joint contractures
  • Serial splinting. Camptodactyly and residual contractures
  • Bracing or fusion. Progressive scoliosis by standard indications
  • Cardiac surveillance. Periodic echocardiography

Complications

  • Severe progressive scoliosis needing early fusion
  • Mitral valve prolapse
  • Recurrent contracture after soft tissue release

Prognosis

  • Limb contractures improve, while scoliosis may progress
  • Normal life expectancy in most

References

  1. Putnam EA, Zhang H, Ramirez F, Milewicz DM. Fibrillin-2 (FBN2) mutations result in the Marfan-like disorder, congenital contractural arachnodactyly. Nat Genet. 1995, 11(4), 456-8. PubMed
  2. Sun L, Huang Y, Zhao S, Zhong W, Shi J, Guo Y, Zhao J, Xiong G, Yin Y, Chen Z, Zhang N, Zhao Z, Li Q, Chen D, Niu Y, Li X, Qiu G, Wu Z, Zhang TJ, Tian W, Wu N. Identification of Novel FBN2 Variants in a Cohort of Congenital Contractural Arachnodactyly. Front Genet. 2022, 13, 804202. PubMed

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 19 October 2026.