Are Patients With Loeys-Dietz Syndrome Misdiagnosed With Beals Syndrome?

Beals syndrome, also known as congenital contractural arachnodactyly (Online Mendelian Inheritance in Man: 121050), is an autosomal dominant disorder caused by a mutation in FBN2 that is typically characterized by congenital contractures and arachnodactyly. It shares a number of phenotypic features with Loeys-Dietz syndrome (Online Mendelian Inheritance in Man: 609192). Loeys-Dietz syndrome, initially described in 2005, is associated with mutations for the transforming growth factor β receptor and is characterized by findings of cerebral, thoracic, and abdominal arterial aneurysms. This report describes a 17-year-old male patient with a typical neonatal diagnosis of Beals syndrome. At age 15 years, an echocardiogram conducted in response to an aortic dissection in his father showed moderate aortic root dilation, prompting comprehensive testing for aortopathies, revealing a mutation in TGFBR1, thereby changing the diagnosis to Loeys-Dietz syndrome. Previously published reports have not implicated any mutation of the transforming growth factor β receptor genes in cases of Beals syndrome. This case underscores that due to significant phenotypic overlap, there is utility in a full panel of testing, including genes for hereditary connective tissue disorders with vascular involvement, as well as FBN2. Likewise, young patients who have tested negative for FBN2 should be tested for hereditary connective tissue disorders with vascular involvement.