Analysis of the fibrillin-1 gene (FBN1) in patients with Marfan syndrome

Thirty exons of the fibrillin-1 gene (FBN1) were screened in patients with Marfan syndrome (MFS), and eleven point mutations, insertions, and deletions were detected. These included two missense mutations resulting in conformational changes of the calcium-binding EGF-like domains of FBN1 and nine polymorphisms located in both coding and noncoding regions of FBN1. Three intragenic polymorphic microsatellite loci—MTS-1, MTS-2, and MTS-4—were analyzed in MFS patients and unrelated healthy controls, and significant differences between these two groups were found for the MTS-2 and MTS-4 allele frequency distributions. Haplotype frequency distributions on wild-type and mutant chromosomes of MFS patients were also significantly different. The predominant haplotype was 2-11-8 on wild-type chromosomes, and 2-2-8 on mutant chromosomes. These data are a prerequisite to working out DNA diagnosis of MFS.