{"doi":"10.1101/2024.03.16.24304180","title":"Splice site and <i>de novo</i> mutations can cause mixed dominant negative/gain of function <i>PLCG2</i> -associated immune dysregulation with cold urticaria (CU-PLAID)","abstract":"Abstract 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 that are classified by mutational effect. PLAID with cold urticaria (CU-PLAID) is caused by in-frame deletions of PLCG2 that are dominant negative at physiologic temperatures but become spontaneously active at sub-physiologic temperatures. Objective To identify genetic lesions that cause PLAID by combining RNA sequencing of full-length PLCG2 with whole genome sequencing. Methods We studied nine probands with antibody deficiency and a positive evaporative cooling test, together with two known CU-PLAID patients and three healthy subjects. Illumina sequencing was performed on full-length PLCG2 cDNA synthesized from peripheral blood mononuclear cell RNA and whole genome sequencing was used to identify genetic lesions. Novel alternate transcripts were overexpressed in the Plcg2- deficient DT40 cell overexpression system. ERK phosphorylation was quantified by flow cytometry with and without BCR crosslinking. Results Two probands expressed novel alternative transcripts of PLCG2 with in-frame deletions. The first, expressing PLCG2 without exons 18-19, carried a splice site mutation in intron 19. The second, expressing PLCG2 without exons 19-22, carried a 14kb de novo deletion of PLCG2 . DT40 cells overexpressing the exon 18-19 or exon 19-22 deletions failed to phosphorylate ERK in response to BCR crosslinking. Conclusion In addition to autosomal dominant genomic deletions, de novo deletions and splice site mutations of PLCG2 can also cause CU-PLAID. All of these can be identified by cDNA-based sequencing. Capsule Summary By identifying both the first de novo and splice site variants to cause PLCG2 -associated immune dysregulation with cold urticaria (CU-PLAID), we demonstrate the diagnostic utility of PLCG2 -specific RNA-sequencing.","journal":"medRxiv","year":2024,"id":495413,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9576,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1029077,"name":"Alexis C. Bailey","orcid":null,"position":1,"is_corresponding":false},{"id":1029076,"name":"Kathleen Baysac","orcid":null,"position":2,"is_corresponding":false},{"id":104191,"name":"Andrew J. Oler","orcid":"0000-0002-6310-0434","position":3,"is_corresponding":false},{"id":225938,"name":"Joshua D. Milner","orcid":"0000-0002-3913-3869","position":4,"is_corresponding":false},{"id":473012,"name":"Michael J. Ombrello","orcid":"0000-0003-3322-4089","position":5,"is_corresponding":false},{"id":85348,"name":"S Chou","orcid":null,"position":0,"is_corresponding":true}],"reference_count":10,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:09:19.627139Z","pmid":"38562814","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}