FBN1 gene mutations in patients with congenital ectopia lentis caused by Marfan syndrome

The prevalence of congenital ectopia lentis is 7–10 cases per 100 000 people. The most common causes of congenital lens displacement are the FBN1 gene mutations that have been found in 25–85 % of patients with this pathology. The aim of the study is to establish the FBN1 gene mutations in patients with congenital lens displacement and in their families. The study group included three families with children and adults suffered from the congenital lens dislocation. The nucleotide sequence of the FBN1 gene was analyzed by direct sequencing. The pathogenicity of the identified mutations was assessed using the Ghent criteria revised in 2010. The mutation c.1884C> G (p.Cys628Trp) in the heterozygous state in the 16th exon of the FBN1 gene was detected in proband 1 and her brother. Proband 2 was found to be a heterozygous career of the mutation c.2461T> A (p.Cys821Ser) in the 21st exon; this mutation was absent in parents and a healthy brother. The mutation c.7851delС (p.Cys2617Trpfs*65) in the heterozygous state in the 64th exon was identified in proband 3 and her mother. In accordance with the revised Ghent classification and the clinical manifestations and molecular genetic studies, Marfan’s syndrome (MS) was diagnosed in all probands and their affected relatives. We detected three pathogenic mutations not previously described in the literature in the 16th, 21st, and 64th exons of the FBN1 gene in patients with congenital ectopia lentis caused by MS. We established the spectrum of clinical manifestations of MS characteristic for the identified mutations.