Clinical variability of the neonatal form of Marfan syndrome in patients with FBN1 gene mutations

Neonatal Marfan syndrome (ORPHA:284979) is a severe form of the syndrome that manifests in infancy and rapidly progresses in childhood. The causative variant of the disease is most often localized in exons 24–32 of the FBN1 gene, in the so-called “neonatal region.” The range of clinical manifestations and their severity depend on the type of mutation, its location and the influence of genetic modifiers. Four clinical cases of the neonatal form of Marfan syndrome are presented. Two patients with the same missense mutations and different clinical presentations, a milder patient with a splice site mutation leading to protein shortening, and a girl with severe skeletal damage with deletion of exons 25–29. The purpose of this publication is to analyze the genotype-phenotype correlation of neonatal Marfan syndrome patients with mutations in exons 24–32 of the FBN1 gene.