Loeys–Dietz syndrome type 4, caused by chromothripsis, involving the TGFB2 gene

• Joints, bones, and retina, as well as aorta, can be involved in Loeys–Dietz type 4.
• In this case a complex rearrangement is responsible for Loeys–Dietz syndrome.
• This is the third reported patient with TGFB2 deletion and intellectual disability.
• Chromotripsis explains the multiple chromosomal break.
• Array-CGH can reveal a great variety of syndromes with complex phenotypes.

The TGF-β signaling pathway controls cellular proliferation, growth and differentiation and regulates several functions of the connective tissue. Disruption of genes coding for components of the TGF-β signaling pathway or its interactors, such as fibrillin-1, has been shown to cause several human pathologies. Large deletions and non-sense mutations in TGFB2 gene have been recently described in patients with aortic aneurysm, scoliosis, arachnodactyly, chest deformities, joint hyper-flexibility, and mild intellectual disability; this condition has been called Loeys–Dietz syndrome, type 4. In this paper we describe an 18-year-old girl with borderline mental impairment, seizures, retinal degeneration, short stature, congenital hip dysplasia, severe and worsening joint hypermobility, scoliosis, progressive deformation of the long bones, aortic dilatation and platelet disorder. Molecular study of DNA by Array-CGH demonstrated four de novo microdeletions: TGFB2 is among the genes deleted and we consider it the obvious candidate for the clinical phenotype. The multiple chromosomal rearrangements detected in the current patient can be ascribed to an event of constitutional chromothripsis.