1. Phenotypic suppression of acral peeling skin syndrome in a patient with autosomal recessive congenital ichthyosis
- Author
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Daphna Weissglas-Volkov, Ofer Sarig, J. Mohamad, Alon Peled, Eli Sprecher, N. Malchin, Noam Shomron, Kiril Malovitski, M. Pavlovsky, John A. McGrath, Rashida Pramanik, and Arti Nanda
- Subjects
Male ,0301 basic medicine ,Heterozygote ,Pathology ,medicine.medical_specialty ,DNA Mutational Analysis ,Lipoxygenase ,Primary Cell Culture ,Hand Dermatoses ,Dermatology ,medicine.disease_cause ,Biochemistry ,ALOXE3 ,Corneodesmosin ,030207 dermatology & venereal diseases ,03 medical and health sciences ,0302 clinical medicine ,Exome Sequencing ,Congenital ichthyosis ,Cell Adhesion ,Humans ,Medicine ,Generalized erythema ,Child ,Molecular Biology ,Cells, Cultured ,Foot Dermatoses ,Mutation ,Transglutaminases ,business.industry ,Ichthyosis ,Homozygote ,Skin Diseases, Genetic ,medicine.disease ,Phenotype ,Pedigree ,030104 developmental biology ,Epidermal Cells ,Female ,medicine.symptom ,business ,Dermatitis, Exfoliative ,Ichthyosis, Lamellar ,Transglutaminase 5 - Abstract
Autosomal recessive congenital ichthyosis (ARCI) manifests with generalized scaling often associated with generalized erythema. Mutations in at least 13 different genes have been reported to cause ARCI. Acral peeling skin syndrome (APSS) is a rare autosomal recessive disorder manifesting with peeling over the distal limbs and dorsal surfaces of hands and feet. APSS is mostly due to mutations in TGM5, encoding transglutaminase 5. Both ARCI and APSS are fully penetrant genetic traits. Here, we describe a consanguineous family in which one patient with mild ARCI was found to carry a homozygous mutation in ALOXE3 (c.1238G > A; p.Gly413Asp). The patient was also found to carry a known pathogenic homozygous mutation in TGM5 (c.1335G > C; p.Lys445Asn) but did not display acral peeling skin. Her uncle carried the same homozygous mutation in TGM5 but carried the ALOXE3 mutation in a heterozygous state and showed clinical features typical of APSS. Taken collectively, these observations suggested that the ALOXE3 mutation suppresses the clinical expression of the TGM5 variant. We hypothesized that ALOXE3 deficiency may affect the expression of a protein capable of compensating for the lack of TGM5 expression. Downregulation of ALOXE3 in primary human keratinocytes resulted in increased levels of corneodesmosin, which plays a critical role in the maintenance of cell-cell adhesion in the upper epidermal layers. Accordingly, ectopic corneodesmosin expression rescued the cell-cell adhesion defect caused by TGM5 deficiency in keratinocytes as ascertained by the dispase dissociation assay. The present data thus provide evidence for phenotypic suppression in a human hereditary skin disorder.
- Published
- 2020
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