A familial case of Marfan syndrome: a novel variant in the FBN1 gene

Marfan syndrome is a hereditary connective tissue disorder characterized by marked pleiotropy and clinical variability. The main disease manifestations involve three systems: skeletal, ocular, and cardiovascular. The condition is caused by pathogenic variants in the FBN1 gene, which encodes fibrillin-1, a protein essential for the formation and maintenance of the extracellular matrix. This article describes a familial case (the proband and his father) with clinical manifestations of Marfan syndrome. Whole-genome sequencing of the proband and his father revealed a previously unreported variant, c.5782T>A, p.(Cys1928Ser), in the FBN1 gene. Thus, a molecular genetic diagnosis of Marfan syndrome was established by identifying this novel pathogenic variant. Conclusion. A confirmed diagnosis at both the clinical and molecular genetic levels in both patients determines the further therapeutic strategy and enables timely primary and secondary disease prevention within the family.