Loeys-Dietz Syndrome Type 4 (LDS4) [I71.1] [I71.2]
Dr. rer. nat. Karin Mayer
In 2012, an additional gene location for TAAD was identified on chromosome 1q41 by both SNP array and linkage analysis and mutations were found in the TGFB2 gene which encodes one of three TGF-β ligands within the TGF-β signal transduction. All of the TGFB2 mutations identified so far cause haploinsufficiency. The types of mutations include entire as well as intragenous genomic deletions as well as point mutations. The frequency of TGFB2 mutations in TAAD is between 0.7 and 7%. The clinical phenotype of patients with TGFB2 mutations matches the phenotype of patients with Loeys-Dietz syndrome. TGFB2 mutations lead, similar to FBN1 and TGFBR1/2 mutations, to an increased TGF-β signal transduction in the arterial wall in affected patients. The disease is also referred to as Loeys-Dietz syndrome type 4 (LDS4).