4-186233981-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_000892.5(KLKB1):​c.251C>T​(p.Thr84Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,658 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T84R) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KLKB1
NM_000892.5 missense

Scores

4
10
3

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 3.23

Publications

0 publications found
Variant links:
Genes affected
KLKB1 (HGNC:6371): (kallikrein B1) This gene encodes a glycoprotein that participates in the surface-dependent activation of blood coagulation, fibrinolysis, kinin generation and inflammation. The encoded preproprotein present in plasma as a non-covalent complex with high molecular weight kininogen undergoes proteolytic processing mediated by activated coagulation factor XII to generate a disulfide-linked, heterodimeric serine protease comprised of heavy and light chains. Certain mutations in this gene cause prekallikrein deficiency. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jan 2016]
KLKB1 Gene-Disease associations (from GenCC):
  • inherited prekallikrein deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.823

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000892.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KLKB1
NM_000892.5
MANE Select
c.251C>Tp.Thr84Ile
missense
Exon 4 of 15NP_000883.2P03952
KLKB1
NM_001440521.1
c.251C>Tp.Thr84Ile
missense
Exon 4 of 14NP_001427450.1
KLKB1
NM_001318394.2
c.137C>Tp.Thr46Ile
missense
Exon 5 of 15NP_001305323.1E9PBC5

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KLKB1
ENST00000264690.11
TSL:1 MANE Select
c.251C>Tp.Thr84Ile
missense
Exon 4 of 15ENSP00000264690.6P03952
ENSG00000290316
ENST00000511608.5
TSL:5
c.392C>Tp.Thr131Ile
missense
Exon 4 of 15ENSP00000426629.1H0YAC1
KLKB1
ENST00000511406.5
TSL:1
n.281C>T
non_coding_transcript_exon
Exon 4 of 15

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461658
Hom.:
0
Cov.:
30
AF XY:
0.00
AC XY:
0
AN XY:
727136
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39666
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111854
Other (OTH)
AF:
0.00
AC:
0
AN:
60384
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.28
BayesDel_addAF
Pathogenic
0.25
D
BayesDel_noAF
Uncertain
0.12
CADD
Benign
22
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.75
D
Eigen
Uncertain
0.54
Eigen_PC
Uncertain
0.42
FATHMM_MKL
Uncertain
0.78
D
LIST_S2
Benign
0.84
T
M_CAP
Uncertain
0.11
D
MetaRNN
Pathogenic
0.82
D
MetaSVM
Pathogenic
0.96
D
PhyloP100
3.2
PrimateAI
Benign
0.42
T
PROVEAN
Pathogenic
-4.6
D
REVEL
Uncertain
0.54
Sift
Uncertain
0.0010
D
Sift4G
Uncertain
0.0030
D
Vest4
0.50
MutPred
0.63
Loss of glycosylation at K89 (P = 0.0306)
MVP
0.95
MPC
0.55
ClinPred
1.0
D
GERP RS
4.7
gMVP
0.62
Mutation Taster
=85/15
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.20
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.20
Position offset: -29

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs756049294; hg19: chr4-187155135; COSMIC: COSV52996837; API