Looks Like Marfan’s Syndrome But It’s Not. Beals–Hecht Syndrome as a Rare Differential Diagnosis

Objectives: Skeletal features are a frequent reason for referral of children to a Marfan’s outpatient clinic. Especially tall stature, arachnodactyly, and hypermobile joints are often presented with the question whether Marfan’s syndrome is the underlying cause. So knowing the differential diagnoses that resemble Marfan’s syndrome is important. Congenital contractural arachnodactyly (Beals–Hecht syndrome, BHS) is a rare disease that presents with arachnodactyly, flexion contractures of multiple joints, scoliosis, highly arched palate, and characteristically crumpled ears. Aortic dilatation is occasionally present but its frequency is unknown. Mitral valve prolapse can be seen in BHS. Thus, the overall prognosis is better than in Marfan’s syndrome. Importantly, no lifestyle changes concerning the risk of aortic aneurysm or dissection have to be taken. The causative mutation is located in the FBN2 gene, and the disorder is inherited in an autosomal-dominant manner.

Result: A 3-year-old girl presented to our Marfan’s outpatient clinic with biconvex scoliosis, arachnodactyly, highly arched palate, positive thumb and wrist sign, and retrognathia. The echocardiography showed a tricuspid valve prolapse but the aorta had normal dimensions. She had no ocular or pulmonal involvement. Her mother had similar skeletal features. Her little sister was unaffected. Genetic testing of the genes FBN1, FBN2, and TGFBR1+2 was performed and revealed the heterozygous mutation c.4150T > A/p. (Cys1384Ser) in FBN2 that is associated with congenital contractural arachnodactyly (Beals–Hecht syndrome). The mother has not yet been tested.

Conclusion: Congenital contractural arachnodactyly or BHS is a rare differential diagnosis of Marfan’s syndrome, especially because skeletal features are similar in both disorders. Crumpled ears are typical of BHS. The important clinical difference is the absence of cardiac involvement in classical BHS; however, in patients with severe BHS, cardiovascular complications can be present. Thus the prognosis is more benign and no lifestyle changes reducing the risk of aortic dissection have to be taken. Confirmation of the clinical diagnosis can be made by genetic testing of the FBN2 gene.