Abstract 13325: Novel Heterozygous EFEMP2 Variant Detected in a Patient with Bilateral Internal Carotid Artery Dissection and Oligodontia

Cutis laxa is a rare connective tissue disorder characterized by sagging or inelastic skin. This phenotype is caused by multiple genotype variants. Biallelic variants in the EFEMP2 gene cause cutis laxa subtype IB characterized by aortic aneurysm, arterial tortuosity, arterial stenosis, joint laxity, arachnodactyly, emphysema, and retrognathia. EFEMP2 encodes fibulin-4, an extracellular matrix protein involved in elastogenesis and modulation of TGF-beta signaling. To date, monoallelic variants in EFEMP2 have not been described as pathogenic. Furthermore, oligodontia has not been associated previously with variants in EFEMP2 . We describe a 67-year-old male with a past medical history of left distal internal carotid artery (ICA) pseudoaneurysm and dissection, right distal ICA dissection, arterial tortuosity, and oligodontia who was found to have a heterozygous variant of uncertain significance in EFEMP2: c.1279_1289del11, p.Arg427CysfsX27. The variant has not been observed previously in large population cohorts and causes a shift in reading frame that substitutes the carboxyl terminal 17 amino acids with 26 alternative amino acids. This carboxyl terminal variant of EFEMP2 has been predicted to interact with PITX2 in yeast two-hybrid analyses. Furthermore, variants in PITX2 have been associated with dental agenesis, including oligodontia. We hypothesize that heterozygous variants in EFEMP2 represent a new syndrome characterized by arteriopathy and dental agenesis.