Reference Expression Profile of Three FBN1 Transcript Isoforms and Their Association with Clinical Variability in...

Area of Science:

• Genetics
• Molecular Biology
• Connective Tissue Disorders

Background:

• Marfan syndrome (MFS) is a rare genetic disorder affecting connective tissue, primarily caused by FBN1 gene mutations.
• Significant variability exists in MFS presentation, including age of onset and symptom severity.
• Previous research indicated FBN1 gene expression levels correlate with certain MFS clinical features.

Purpose of the Study:

• To investigate if specific FBN1 gene isoforms contribute to the phenotypic variability observed in Marfan syndrome.
• To analyze the expression profiles of FBN1 isoforms in fibroblasts from MFS patients and healthy controls.

Main Methods:

• Fibroblast cultures were established from MFS patients and controls.
• Quantitative analysis of FBN1 alternative transcript isoforms (FBN1_001, FBN1_004, FBN1_009) was performed using skin and adventitial fibroblasts.
• Correlations between isoform expression levels and clinical manifestations, such as ectopia lentis, were assessed.

Main Results:

• Only three FBN1 isoforms (FBN1_001, FBN1_004, FBN1_009) were detected in fibroblasts.
• The primary isoform, FBN1_001, was significantly reduced in MFS patient fibroblasts compared to controls.
• Expression of FBN1_004 and FBN1_009 isoforms did not differ between groups, but their levels correlated in MFS patients and were associated with ectopia lentis.

Conclusions:

• The study suggests that alternative splicing of the FBN1 gene, particularly involving minor isoforms FBN1_004 and FBN1_009, may play a role in Marfan syndrome pathogenesis.
• Differential expression and correlation of FBN1 isoforms are linked to clinical variability, including ocular complications like ectopia lentis.