Characterization of microsatellite markers flanking FBN1: Utility in the diagnostic evaluation for Marfan syndrome

Daniel P. Judge, Nancy J. Biery, Harry C. Dietz

Research output: Contribution to journalArticle

Abstract

Marfan syndrome (MFS) is an autosomal dominant disorder of connective tissue with marked interfamilial and intrafamilial variation in phenotype. The primary defect in affected patients resides in the gene for fibrillin-1 (FBN1) on 15q21. Linkage analysis has shown no locus heterogeneity in the classic phenotype, although substantial allelic heterogeneity exists. Recently it has been shown that the size of the gene is approximately 200 kb. These and other factors have precluded routine mutation screening for presymptomatic and prenatal diagnosis. Previously we described four intragenic microsatellite polymorphisms that can be used for haplotype segregation analysis. The utility of this approach is limited because the markers do not fully span the gene and show incomplete informativeness, with 16% homozygosity for the most common haplotype. We have now identified and localized highly polymorphic microsatellite markers that fall within 1 Mb of FBN1. Complete haplotype heterozygosity was observed in a population of 50 unrelated control individuals when the flanking markers and existing intragenic polymorphisms were used in combination. We demonstrate the utility of haplotype segregation analysis in the presymptomatic diagnosis and counseling of families showing atypical or equivocal manifestations of MFS.

Original languageEnglish (US)
Pages (from-to)39-47
Number of pages9
JournalAmerican journal of medical genetics
Volume99
Issue number1
DOIs
StatePublished - Feb 15 2001

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Keywords

  • FBN1 gene
  • Fibrillin-1
  • Haplotype segregation analysis
  • Marfan syndrome
  • Molecular diagnosis

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

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