Total submissions: 3
Submitter | RCV | SCV | Clinical significance | Condition | Last evaluated | Review status | Method | Comment |
---|---|---|---|---|---|---|---|---|
Institute for Clinical Chemistry and Laboratory Medicine, |
RCV002467395 | SCV002761960 | pathogenic | Inherited prekallikrein deficiency | 2022-12-06 | criteria provided, single submitter | clinical testing | We have detected this variant, NM_000892.4(KLKB1):c.1204_1205delTG p.(Trp402Alafs*35), in two siblings via Sanger sequencing in heterozygosity (PMID: 32202057; slightly misnamed as c.1203_1204delGT, since the 3'-rule was not followed). Their aPTTs were within the usual reference ranges but they showed slightly decreased prekallikrein (PK) levels (case1: 66% PK activity, 43% PK antigen; case2: 59% PK activity, 34% PK antigen). Their father was known to be completely PK deficient (5% PK activity, 2% PK antigen) and was published by Asmis et al (PMID: 12091043). This small deletion has a global MAF of ~0.01% (dbSNP) and likely results in a frameshift at protein level with a premature stop codon. In addition, it includes a base position that has already been described as a cause of PK deficiency in the literature in a compound heterozygous case (PMID: 14652634). Therefore, we classified this variant as pathogenic in accordance with ACMG guidelines. |
Prevention |
RCV003395482 | SCV004120535 | likely pathogenic | KLKB1-related disorder | 2023-01-27 | criteria provided, single submitter | clinical testing | The KLKB1 c.1204_1205delTG variant is predicted to result in a frameshift and premature protein termination (p.Trp402Alafs*35). This variant was reported in an individual with Prekallikrein (PK) deficiency; however, zygosity of this variant was not clearly established in this patient (Case #4 in Barco et al. 2020. PubMed ID: 32202057). This variant is reported in 0.026% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/4-187173228-AGT-A). Frameshift variants in KLKB1 are expected to be pathogenic. This variant is interpreted as likely pathogenic. |
Department of Pathology and Laboratory Medicine, |
RCV002467395 | SCV005918669 | likely pathogenic | Inherited prekallikrein deficiency | 2022-08-29 | criteria provided, single submitter | research |