Comprehensive clinical and molecular analysis of 12 families with type 1 recessive cutis laxa.

Abstract

Autosomal recessive cutis laxa type I (ARCL type I) is characterized by generalized cutis laxa with pulmonary emphysema and/or vascular complications. Rarely, mutations can be identified in FBLN4 or FBLN5. Recently, LTBP4 mutations have been implicated in a similar phenotype. Studying FBLN4, FBLN5, and LTBP4 in 12 families with ARCL type I, we found bi-allelic FBLN5 mutations in two probands, whereas nine probands harbored biallelic mutations in LTBP4. FBLN5 and LTBP4 mutations cause a very similar phenotype associated with severe pulmonary emphysema, in the absence of vascular tortuosity or aneurysms. Gastrointestinal and genitourinary tract involvement seems to be more severe in patients with LTBP4 mutations. Functional studies showed that most premature termination mutations in LTBP4 result in severely reduced mRNA and protein levels. This correlated with increased transforming growth factor-beta (TGFβ) activity. However, one mutation, c.4127dupC, escaped nonsense-mediated decay. The corresponding mutant protein (p.Arg1377Alafs(*) 27) showed reduced colocalization with fibronectin, leading to an abnormal morphology of microfibrils in fibroblast cultures, while retaining normal TGFβ activity. We conclude that LTBP4 mutations cause disease through both loss of function and gain of function mechanisms.

• Authors: Bert Callewaert, Chi-Ting Su, Tim Van Damme, Philip Vlummens, Fransiska Malfait, Olivier Vanakker, Bianca Schulz, Meghan Mac Neal, Elaine C Davis, Joseph G H Lee, Aicha Salhi, Sheila Unger, Ketil Heimdal, Salome De Almeida, Uwe Kornak, Harald Gaspar, Jean-Luc Bresson, Katrina Prescott, Maria E Gosendi, Sahar Mansour, Gérald E Piérard, Suneeta Madan-Khetarpal, Frank C Sciurba, Sofie Symoens, Paul J Coucke, Lionel Van Maldergem, Zsolt Urban, Anne De Paepe
• Journal: Human mutation (Hum Mutat) Vol. 34 Issue 1 Pg. 111-21 (Jan 2013) ISSN: 1098-1004 [Electronic] United States
• PMID: 22829427 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 Wiley Periodicals, Inc.

Chemical References

• EFEMP2 protein, human
• Extracellular Matrix Proteins
• FBLN5 protein, human
• LTBP4 protein, human
• Latent TGF-beta Binding Proteins

Topics

• Adolescent
• Base Sequence
• Blotting, Western
• Child
• Child, Preschool
• Consanguinity
• Cutis Laxa (complications, genetics)
• Extracellular Matrix Proteins (genetics, metabolism)
• Family Health
• Female
• Gene Expression
• Humans
• Infant
• Latent TGF-beta Binding Proteins (genetics, metabolism)
• Male
• Microscopy, Electron
• Mutation
• Pedigree
• Pulmonary Emphysema (complications)
• Reverse Transcriptase Polymerase Chain Reaction
• Sequence Analysis, DNA
• Skin (metabolism, pathology, ultrastructure)
• Young Adult