{"id":1791,"system":{"id":22,"isbt_number":22,"name":"Knops","symbol":"KN","category":"Blood Group System","approved":true,"version":15,"createdAt":"2024-04-29T09:32:29.074Z","updatedAt":"2025-09-24T11:13:50.676Z","description":"The Knops blood group system consists of 9 antigens carried on a glycoprotein of 2039 amino acids and called the Complement Receptor I (CR1). It has a leader sequence of 41 to 46 amino acids, depending on translation initiation site, which is cleaved from the membrane protein. The coding sequence starts at nucleotide 28. The Helgeson phenotype, initially thought to be a KN serologic null, may be more likely the result of lower-level CR1 density and may also involve lack of a high-prevalence KN antigen [Pham Transfusion 2010 50(7):1435-43].","allele_notes":"","assignees":["Margaret Keller"]},"gene":{"id":28,"name":"CR1","isbt_gene":"NG_007481.1","isbt_transcript":"NM_000573.4","isbt_protein":"NP_000642.3","approved":true,"createdAt":"2024-04-29T09:33:06.773Z","updatedAt":"2024-05-06T16:34:48.794Z","version":1,"initiation_codon":null,"stop_codon":null,"entrez_id":1378,"chromosome":"1","hg19_start":207669172,"hg19_end":207815109,"hg38_start":207496156,"hg38_end":207641765,"exon_count":39},"reference_allele":false,"sv_allele":false,"null_allele":false,"mod_allele":false,"partial_allele":false,"weak_allele":true,"el_allele":false,"allele_order":null,"isbt_allele":"KN*01W","alternate_names":null,"isbt_phenotype":"Helgeson Phenotype","isbt_snp":"NM_000573.4:c.488-2599T>C","table_row_group":null,"notes":null,"approved":true,"comment":null,"deleted":false,"obsolete":false,"provisional":false,"phenotypes":[],"variants":[{"id":1580,"input":"NM_000573.4:c.488-2599T>C","note":"The current status of LRG_814 is pending therefore changes may be made to the LRG reference sequence","hgvs_transcript":"NM_000573.4:c.488-2599T>C","exon":"4i","intron":null,"rsid":"rs11117991","hgvs_intronic_chr_context":"NC_000001.11(NM_000573.4):c.488-2599T>C","hgvs_intronic_rsg_context":"NG_007481.1(NM_000573.4):c.488-2599T>C","hgvs_refseqgene":"NG_007481.1:g.29885T>C","hgvs_lrg":"LRG_814:g.29885T>C","hgvs_lrg_transcript":null,"hgvs_predicted_protein":"NP_000564.2:p.?","hgvs_genomic_grch37":"NC_000001.10:g.207694357T>C","hgvs_genomic_grch38":"NC_000001.11:g.207521012T>C","grch37_chr":"1","grch37_pos":207694357,"grch37_ref":"T","grch37_alt":"C","grch38_chr":"1","grch38_pos":207521012,"grch38_ref":"T","grch38_alt":"C","freeform_dna_change":null,"freeform_exon":null,"freeform_intron":null,"freeform_predicted_protein":null,"alternative_splicing":false,"gene_name":"CR1","approved":true,"gnomad_all":0.1573162778288323,"gnomad_afr":0.03765026714158504,"gnomad_amr":0.21360418590335487,"gnomad_asj":0.2892835641180012,"gnomad_eas":0.27062937062937065,"gnomad_fin":0.1568602261048304,"gnomad_nfe":0.1832088615539099,"gnomad_remaining":0.16703296703296702,"gnomad_sas":0.3835965359144167,"gnomad_mid":0.1984732824427481,"gnomad_ami":0.25116279069767444,"createdAt":"2024-10-17T17:52:51.961Z","updatedAt":"2026-04-02T14:12:11.175Z","version":3}],"genbanks":[],"publications":[{"id":634,"identifier":"37591894","citation":"Wu PC, Lee YQ, Möller M, Storry JR, Olsson ML. Elucidation of the low-expressing erythroid CR1 phenotype by bioinformatic mining of the GATA1-driven blood-group regulome. Nat Commun. 2023 Aug;1(14):5001.","type":"pmid","createdAt":"2024-09-29T12:17:35.711Z","updatedAt":"2024-09-29T12:17:35.711Z","version":1}],"createdBy":{"username":"Nick Gleadall"},"updatedBy":{"username":"Nick Gleadall"},"createdAt":"2024-10-17T22:28:48.995Z","updatedAt":"2026-04-02T14:12:11.248Z","version":2}