A novel mutation of the fibrillin gene causing ectopia lentis.

Abstract

Ectopia lentis (EL), a dominantly inherited connective tissue disorder, has been genetically linked to the fibrillin gene on chromosome 15 (FBN1) in earlier studies. Here, we report the first EL mutation in the FBN1 gene confirming that EL is caused by mutations of this gene. So far, several mutations in the FBN1 gene have been reported in patients with Marfan syndrome (MFS). EL and MFS are clinically related but distinct conditions with typical manifestations in the ocular and skeletal systems, the fundamental difference between them being the absence of cardiovascular involvement in EL. We report a point mutation, cosegregating with the disease in the described family, that displays EL over four generations. The mutation changes a conserved glutamic acid residue in an EGF-like motif, which is the major structural component of the fibrillin and is repeated throughout the polypeptide. In vitro mutagenetic studies have demonstrated the necessity of an analogous glutamic acid residue for calcium binding in an EGF-like repeat of human factor IX. This provides a possible explanation for the role of this mutation in the disease pathogenesis.

• Authors: L Lönnqvist, A Child, K Kainulainen, R Davidson, L Puhakka, L Peltonen
• Journal: Genomics (Genomics) Vol. 19 Issue 3 Pg. 573-6 (Feb 1994) ISSN: 0888-7543 [Print] United States
• PMID: 8188302 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• FBN1 protein, human
• Fibrillin-1
• Fibrillins
• Microfilament Proteins

Topics

• Amino Acid Sequence
• Base Sequence
• Chromosomes, Human, Pair 15
• DNA Mutational Analysis
• Ectopia Lentis (genetics)
• Female
• Fibrillin-1
• Fibrillins
• Genes
• Humans
• Male
• Marfan Syndrome (genetics)
• Microfilament Proteins (deficiency, genetics)
• Molecular Sequence Data
• Pedigree
• Phenotype
• Point Mutation