A potential founder variant inCARMIL2/RLTPRin three Norwegian families with warts, molluscum contagiosum, and T-cell dysfunction
Open Access
- 17 September 2016
- journal article
- research article
- Published by Wiley in Molecular Genetics & Genomic Medicine
- Vol. 4 (6), 604-616
- https://doi.org/10.1002/mgg3.237
Abstract
Four patients from three Norwegian families presented with a common skin phenotype of warts, molluscum contagiosum, and dermatitis since early childhood, and various other immunological features. Warts are a common manifestation of human papilloma virus (HPV), but when they are overwhelming, disseminated and/or persistent, and presenting together with other immunological features, a primary immunodeficiency disease (PIDD) may be suspected. The four patients were exome sequenced as part of a larger study for detecting genetic causes of primary immunodeficiencies. No disease‐causing variants were identified in known primary immunodeficiency genes or in other disease‐related OMIM genes. However, the same homozygous missense variant in CARMIL2 (also known as RLTPR) was identified in all four patients. In each family, the variant was located within a narrow region of homozygosity, representing a potential region of autozygosity. CARMIL2 is a protein of undetermined function. A role in T‐cell activation has been suggested and the mouse protein homolog (Rltpr) is essential for costimulation of T‐cell activation via CD28, and for the development of regulatory T cells. Immunophenotyping demonstrated reduced regulatory, CD4+ memory, and CD4+ follicular T cells in all four patients. In addition, they all seem to have a deficiency in IFN γ ‐synthesis in CD4+ T cells and NK cells. We report a novel primary immunodeficiency, and a differential molecular diagnosis to CXCR4‐,DOCK8‐,GATA2‐,MAGT1‐,MCM4‐,STK4‐,RHOH‐,TMC6‐, and TMC8‐related diseases. The specific variant may represent a Norwegian founder variant segregating on a population‐specific haplotype.Keywords
Funding Information
- National Human Genome Research Institute
- National Heart, Lung, and Blood Institute (U54HG006542)
- South-Eastern Norway Health Authority
This publication has 38 references indexed in Scilit:
- The Phyre2 web portal for protein modeling, prediction and analysisNature Protocols, 2015
- Tissue-based map of the human proteomeScience, 2015
- The Mouse Genome Database (MGD): facilitating mouse as a model for human biology and diseaseNucleic Acids Research, 2014
- Identification of copy number variants from exome sequence dataBMC Genomics, 2014
- The lymphoid lineage–specific actin-uncapping protein Rltpr is essential for costimulation via CD28 and the development of regulatory T cellsNature Immunology, 2013
- An integrated map of genetic variation from 1,092 human genomesNature, 2012
- Distinct Roles for CARMIL Isoforms in Cell MigrationMolecular Biology of the Cell, 2009
- Jalview Version 2—a multiple sequence alignment editor and analysis workbenchBioinformatics, 2009
- The leucine-rich repeat structureCellular and Molecular Life Sciences, 2008
- Identification, expression analysis and polymorphism of a novel RLTPR gene encoding a RGD motif, tropomodulin domain and proline/leucine-rich regionsGene, 2004