All of the following are chromosomal breakage syndromes except

Ref Robbins 7/e p 155_156; table 5.5,174,9/e p145-146 defective synthesis of the scaffolding protein fibrillin leads to abnormal sequestration of TGF-b in the aoic wall, with subsequent dilation due to dysregulated signaling and progressive loss of elastic tissue. Defective type III collagen synthesis with aneurysm formation is a hallmark of the type IV Ehlers-Danlos syndrome Mutations in at least 19 genes have been found to cause the Ehlers-Danlos syndromes. Mutations in the COL5A1 or COL5A2 gene, or rarely in the COL1A1 gene, can cause the classical type. Mutations in the TNXB gene cause the classical-like type and have been repoed in a very small percentage of cases of the hypermobile type (although in most people with this type, the cause is unknown). The cardiac-valvular type and some cases of the ahrochalasia type are caused by COL1A2 gene mutations; mutations in the COL1A1gene have also been found in people with the ahrochalasia type.