Two rare missense mutations in the fibrillin-1 gene associated with atypical cardiovascular manifestations in a Chinese patient affected by Marfan syndrome

The present report aimed to evaluate the results of screen mutations of the fibrillin (FBN) 1 gene and analyze the symptoms in one Chinese patient clinically diagnosed with Marfan syndrome (MFS). Clinical data were collected and FBN1 gene sequencing was performed. Genomic DNA was extracted from the blood sample of the patient. All 65 exons were screened using a polymerase chain reaction assay. The diagnosis of MFS was confirmed via identification of symptoms presenting in the skeletal system (arachnodactyly, walker wrist and thumb signs) and the ocular system (ectopia lentis), in addition to a positive family history. The patient's cardiovascular manifestations (dilatation of the four cardiac chambers, severe mitral valve regurgitation and a large saccular aneurysm of the non-coronary sinus of Valsalva) were atypical to those that most frequently occur in cases of MFS. Following gene sequencing, two novel heterozygous mutations of the FBN-1 gene were identified: c.3442C>G in exon 27, proline replaced with alanine (p. Pro1148Ala) and c.6388G>A in exon 52, glutamic acid replaced with lysine (p. Glu2130Lys). The clinical symptoms and family history were important in the diagnosis of MFS, however the atypical signs that presented in the cardiovascular system may be associated with the disease, and may be noted for further cases in the future. Gene sequencing further verified the correct diagnosis of MFS.