Homozygous mutations in the 5' region of the JUP gene result in cutaneous disease but normal heart development in children.

Abstract

Desmosomes are intercellular adhesive junctions and attachment sites for the intermediate filament (IF) cytoskeleton, prominent in tissues subject to high levels of mechanical stress such as the epidermis and heart. The obligate desmosomal constituent, plakoglobin (PG), is involved in coupling transmembrane desmosomal components with IFs. PG also contributes to intercellular adhesion through adherens junctions and has additional signaling roles. To date, two mutations in the gene encoding PG, JUP, have been described, and in both instances, patients harboring pathogenic mutations suffered from arrhythmogenic right ventricular cardiomyopathy with or without skin abnormalities. We describe homozygous nonsense mutation, p.S24X, and homozygous splice site mutation, c.468G>A, in the JUP gene that results in skin fragility, diffuse palmoplantar keratoderma, and woolly hair with no symptoms of cardiomyopathy. We show barely detectable levels of PG immunostaining in skin sections from patients harboring these mutations and show that an alternative AUG codon in p.S24X mRNA translates a 42-amino-acid N-terminal truncation. We conclude that PG is required for correct maintenance of skin integrity, and the absence of heart phenotype in patients suggests that aberrant PG expression does not compromise normal human heart development in children. Our findings provide new insight into the distinct roles that PG has in the epidermis and heart.

• Authors: Rita M Cabral, Lu Liu, Carol Hogan, Patricia J C Dopping-Hepenstal, Beatriz C Winik, Raúl A Asial, Richard Dobson, Charles A Mein, Patricia A Baselaga, Jemima E Mellerio, Arti Nanda, Maria del Carmen Boente, David P Kelsell, John A McGrath, Andrew P South
• Journal: The Journal of investigative dermatology (J Invest Dermatol) Vol. 130 Issue 6 Pg. 1543-50 (Jun 2010) ISSN: 1523-1747 [Electronic] United States
• PMID: 20130592 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Codon, Nonsense
• DNA, Complementary
• Desmoplakins
• JUP protein, human
• RNA Splice Sites
• RNA, Messenger
• gamma Catenin

Topics

• Biopsy
• Cardiomyopathies (genetics, physiopathology)
• Child
• Child, Preschool
• Codon, Nonsense (genetics)
• DNA, Complementary (genetics)
• Desmoplakins (genetics, physiology)
• Female
• Heart (growth & development, physiology)
• Homozygote
• Humans
• Infant
• Male
• Nucleic Acid Amplification Techniques
• Phenotype
• Polymorphism, Single Nucleotide (genetics)
• RNA Splice Sites (genetics)
• RNA, Messenger (genetics)
• Skin (pathology, ultrastructure)
• Skin Diseases, Genetic (genetics, physiopathology)
• gamma Catenin