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Li MWY, Burnett L, Dai P, Avery DT, Noori T, Voskoboinik I, Shah PR, Tatian A, Tangye SG, Gray PE, Ma CS. Filaggrin-Associated Atopic Skin, Eye, Airways, and Gut Disease, Modifying the Presentation of X-Linked Reticular Pigmentary Disorder (XLPDR). J Clin Immunol 2024; 44:38. [PMID: 38165470 DOI: 10.1007/s10875-023-01637-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 12/02/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND X-linked reticular pigmentary disorder (XLPDR) is a rare condition characterized by skin hyperpigmentation, ectodermal features, multiorgan inflammation, and recurrent infections. All probands identified to date share the same intronic hemizygous POLA1 hypomorphic variant (NM_001330360.2(POLA1):c.1393-354A > G) on the X chromosome. Previous studies have supported excessive type 1 interferon (IFN) inflammation and natural killer (NK) cell dysfunction in disease pathogenesis. Common null polymorphisms in filaggrin (FLG) gene underlie ichthyosis vulgaris and atopic predisposition. CASE A 9-year-old boy born to non-consanguineous parents developed eczema with reticular skin hyperpigmentation in early infancy. He suffered recurrent chest infections with chronic cough, clubbing, and asthma, moderate allergic rhinoconjunctivitis with keratitis, multiple food allergies, and vomiting with growth failure. Imaging demonstrated bronchiectasis, while gastroscopy identified chronic eosinophilic gastroduodenitis. Interestingly, growth failure and bronchiectasis improved over time without specific treatment. METHODS Whole-genome sequencing (WGS) using Illumina short-read sequencing was followed by both manual and orthogonal automated bioinformatic analyses for single-nucleotide variants, small insertions/deletions (indels), and larger copy number variations. NK cell cytotoxic function was assessed using 51Cr release and degranulation assays. The presence of an interferon signature was investigated using a panel of six interferon-stimulated genes (ISGs) by QPCR. RESULTS WGS identified a de novo hemizygous intronic variant in POLA1 (NM_001330360.2(POLA1):c.1393-354A > G) giving a diagnosis of XLPDR, as well as a heterozygous nonsense FLG variant (NM_002016.2(FLG):c.441del, NP_0020.1:p.(Arg151Glyfs*43)). Compared to healthy controls, the IFN signature was elevated although the degree moderated over time with the improvement in his chest disease. NK cell functional studies showed normal cytotoxicity and degranulation. CONCLUSION This patient had multiple atopic manifestations affecting eye, skin, chest, and gut, complicating the presentation of XLPDR. This highlights that common FLG polymorphisms should always be considered when assessing genotype-phenotype correlations of other genetic variation in patients with atopic symptoms. Additionally, while the patient exhibited an enhanced IFN signature, he does not have an NK cell defect, suggesting this may not be a constant feature of XLPDR.
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Affiliation(s)
- Margaret W Y Li
- Department of Allergy and Immunology, Sydney Children's Hospital, Sydney, Australia.
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia.
| | - Leslie Burnett
- Garvan Institute of Medical Research, Sydney, Australia
- Clinical Immunogenomics Research Consortium Australasia (CIRCA), Sydney, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, St Vincent's Healthcare Clinical Campus, UNSW Sydney, Sydney, Australia
| | - Pei Dai
- Garvan Institute of Medical Research, Sydney, Australia
- Clinical Immunogenomics Research Consortium Australasia (CIRCA), Sydney, Australia
| | | | | | | | - Parth R Shah
- Department of Ophthalmology, Sydney Children's Hospital, Sydney, Australia
| | - Artiene Tatian
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia
- Department of Dermatology, Sydney Children's Hospital, Sydney, Australia
| | - Stuart G Tangye
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
- Clinical Immunogenomics Research Consortium Australasia (CIRCA), Sydney, Australia
| | - Paul E Gray
- Department of Allergy and Immunology, Sydney Children's Hospital, Sydney, Australia.
- Clinical Immunogenomics Research Consortium Australasia (CIRCA), Sydney, Australia.
- School of Medicine, Western Sydney University, Sydney, Australia.
| | - Cindy S Ma
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Sydney, Australia
- Garvan Institute of Medical Research, Sydney, Australia
- Clinical Immunogenomics Research Consortium Australasia (CIRCA), Sydney, Australia
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