C596G mutation in FBN1 causes Marfan syndrome with exotropia in a Chinese family.

To screen mutations in the fibrillin-1 (FBN1) gene in a Chinese family with autosomal dominant Marfan syndrome (MFS). Patients and unaffected family members were given ophthalmic, cardiovascular, and physical examinations with a 5-year follow-up. Genomic DNA was extracted from the leukocytes of venous blood from all patients and their relatives. The entire coding region of the FBN1gene was screened with an ABI 9700 GeneAmp PCR System. The mutation identified was screened in 100 healthy and ethnically unrelated Chinese individuals. Mutation screening in FBN1 identified a T>G transition at position c.1786 in exon 14, leading to substitution of cysteine for glycine at codon 596 (C596G) in this four-generation Chinese family. The C596G mutation was associated with the disease phenotypes in all six patients but not found in 14 unaffected family members or the 100 ethnically unrelated and healthy controls. A C596G mutation in FBN1 was identified in a Chinese family with MFS. Our results expand the spectrum of FBN1 mutations and contribute to the understanding of the role of FBN1 in the pathogenesis of Marfan syndrome.