A 5-year-old boy presented with generalized cutaneous erosions, severe scarring, depigmentation and contractures affecting major joints. The lesions had initially affected his ears, nose, feet, and the genital and ocular mucosa, leading to significant depigmentation, scarring, contractures and mutilation. The whole of the trunk and limbs were involved at the time of presentation, with the exception of some islands of spared skin on the proximal thighs, legs, nipples and external genitalia. Electron microscopy revealed a split in the sublamina densa with the absence of anchoring fibrils, suggestive of dystrophic epidermolysis bullosa (EB). Immunofluorescence antigen mapping demonstrated a broad reticulate pattern of staining with collagen IV, VII, and laminin 332 in the floor of the blister, suggestive of Kindler syndrome. Next-generation sequencing revealed a de novo heterozygous missense mutation (a variant of unknown significance) in exon 22 of the phospholipase-C gamma 2 gene (PLCG2), which resulted in a substitution of serine by asparagine at codon 798 (p.Asp798Ser), a result that was validated using Sanger sequencing. The child was diagnosed with PLCG2-associated antibody deficiency and immune dysregulation (PLAID)/autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) syndrome. The cutaneous and corneal erosions, inflammation and scarring of this magnitude, and the eventual result of death have not been described previously for the PLAID/APLAID spectrum previously. In conclusion, this was an unusual acquired autoinflammatory severe EB-like disease that may be associated with de novo PLCG2 mutation.
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http://dx.doi.org/10.1111/ced.14557 | DOI Listing |
J Allergy Clin Immunol
December 2024
Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health (NIH), Bethesda, Md. Electronic address:
Background: Phospholipase Cγ2 (PLCγ2) is an important signaling molecule that receives and transmits signals from various cell surface receptors in most hematopoietic lineages. Variants of PLCG2 cause PLCγ2-associated immune dysregulation (PLAID), a family of conditions classified by mutational effect. PLAID with cold urticaria (PLAID-CU) is caused by in-frame deletions of PLCG2 that are dominant negative at physiologic temperatures but become spontaneously active at subphysiologic temperatures.
View Article and Find Full Text PDFJ Allergy Clin Immunol
December 2024
Department of Pediatrics, Division of Allergy, Immunology, and Rheumatology, Columbia University, New York, NY. Electronic address:
Background: Cherubism is most commonly caused by rare heterozygous gain-of-function (GOF) missense variants in SH3BP2, which appear to signal through phospholipase C gamma 2 (PLCG2) to cause excessive osteoclast activity leading to expansile lesions in facial bones in childhood. GOF variants in PLCG2 lead to autoinflammatory PLCG2-associated antibody deficiency and immune dysregulation (autoinflammatory PLAID, or PLAID-GOF), characterized by variably penetrant autoinflammatory, autoimmune, infectious, and atopic manifestations. Cherubism has not been reported in PLAID to date.
View Article and Find Full Text PDFmedRxiv
March 2024
Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health (NIH), Bethesda, MD.
Background: Phospholipase Cγ2 (PLCγ2) is an important signaling molecule that receives and transmits signals from various cell surface receptors in most hematopoietic lineages. Variants of cause PLCγ2-associated immune dysregulation (PLAID), a family of conditions that are classified by mutational effect. PLAID with cold urticaria (CU-PLAID) is caused by in-frame deletions of that are dominant negative at physiologic temperatures but become spontaneously active at sub-physiologic temperatures.
View Article and Find Full Text PDFJ Allergy Clin Immunol
January 2024
Translational Genetics and Genomics Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Md. Electronic address:
Background: Pathogenic variants of phospholipase C gamma 2 (PLCG2) cause 2 related forms of autosomal-dominant immune dysregulation (ID), PLCγ2-associated antibody deficiency and immune dysregulation (PLAID) and autoinflammatory PLAID (APLAID). Since describing these conditions, many PLCG2 variants of uncertain significance have been identified by clinical sequencing of patients with diverse features of ID.
Objective: We sought to functionally classify PLCG2 variants and explore known and novel genotype-function-phenotype relationships.
Rheumatology (Oxford)
September 2023
Department of Rheumatology and Clinical Immunology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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