[Recurrent N1173K mutation in FBN1 gene in a Chinese family with ectopia lentis]

To study the disease-causing gene mutation in a Chinese family with ectopia lentis.

The phenotype of each family member in a Chinese family with ectopia lentis was identified by detailed clinical examination. The inheritance mode in this family was ascertained by the pedigree analysis. Linkage analysis was performed by microsatellite markers on chromosome 15 and LOD Score was calculated by Mlink program. Gene mutations were detected by sequence analysis to the whole coding region and exon-intron boundaries of the candidate gene.

A significant LOD score of 3.01 was obtained at D15S978 on chromosome 15q21.1, where FBN1 gene was located. A C3519G change in exon 29 of FBN1 gene, resulting in asparagine change to lysine at codon 1173, was detected by direct sequence analysis. This mutation was absent in the normal family members and 100 normal controls.

Our results indicate that c.C3519G (p.N1173K) mutation in FBN1 gene is the underlying molecular pathogenesis of this family with ectopia lentis.