Genomic Observations of a Rare/Pathogenic Variant in Loeys⁻Dietz Syndrome 3 Confirmed by Protein Informatics and Structural Investigations.

Loeys-Dietz syndrome 3, also known as aneurysms--osteoarthritis syndrome, is an autosomal dominant genetic connective tissue disease caused by pathogenic variants in , a transcription factor involved in TGF-β signaling. This disorder is characterized by early-onset osteoarthritis and arterial aneurysms. Common features include scoliosis, uvula abnormalities, striae, and velvety skin. : The pathogenicity of a variant of uncertain significance in the gene was evaluated (variant c.220C > T) through personalized protein informatics and molecular studies. The case of a 44-year-old male, who was originally presumed to have Marfan syndrome, is presented. An expanded gene panel determined the probable cause to be a variant in , c.220C > T (p.R74W). His case was complicated by a history of stroke, but his phenotype was otherwise characteristic for Loeys-Dietz syndrome 3. This case emphasizes the importance of comprehensive genetic testing to evaluate patients for connective tissue disorders, as well as the potential benefit of utilizing a protein informatics platform for the assessment of variant pathogenicity.