Novel FBN1 mutations associated with predominant ectopia lentis and marfanoid habitus in Chinese patients

Abstract

Purpose: To identify mutations in the fibrillin-1 gene (FBN1) and provide further information about genotype-phenotype correlations in Chinese patients with predominant ectopia lentis (EL) and marfanoid habitus.

Methods: Patients from seven Chinese families underwent complete physical, ophthalmic, and cardiovascular examination. Genomic DNA was extracted from leukocytes of peripheral blood from the patients. The 65 exons and flanking intronic sequences of FBN1 were amplified by polymerase chain reaction (PCR) and screened for mutation by direct DNA sequencing.

Results: Three novel mutations, c.203G>T in exon 2, c.502T>C in exon 5, and c.2096G>C in exon 16 as well as four known mutations, c.364C>T in exon 4, c.1633C>T in exon 13, c.1879C>T in exon 15, and c.4588C>T in exon37, were identified in FBN1.

Conclusions: We identified three novel mutations and four known mutations in FBN1 and found cysteine substitution highly related to EL. These results expand the mutation spectrum in FBN1 and enrich our knowledge of genotype-phenotype correlations due to FBN1 mutations. To our knowledge, this is the first report of cysteine residue loss in the unique NH2-terminal domain of fibrillin-1.