The type of FBN1 variant identified and the likelihood of that variant being pathogenic are recognized as important factors when diagnosing MFS, with de novo (in the absence of family history), nonsense, frameshift, splicing, and missense substitutions of conserved residues considered most likely to be pathogenic [9]. Identifying pathogenic or likely pathogenic variants in the FBN1 gene, linked with specific clinical manifestations such as aortic root enlargement or lens dislocation, plays a crucial role in diagnosing MFS [10]. The gene discussed is FBN1; the disease is Marfan syndrome.