4-186228218-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000892.5(KLKB1):​c.23C>T​(p.Thr8Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000208 in 1,588,812 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T8P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

KLKB1
NM_000892.5 missense

Scores

18

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.439
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
KLKB1NM_000892.5 linkuse as main transcriptc.23C>T p.Thr8Ile missense_variant 2/15 ENST00000264690.11

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
KLKB1ENST00000264690.11 linkuse as main transcriptc.23C>T p.Thr8Ile missense_variant 2/151 NM_000892.5 P1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152142
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000200
AC:
5
AN:
250418
Hom.:
0
AF XY:
0.0000148
AC XY:
2
AN XY:
135340
show subpopulations
Gnomad AFR exome
AF:
0.0000618
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000265
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
0.0000216
AC:
31
AN:
1436670
Hom.:
0
Cov.:
27
AF XY:
0.0000140
AC XY:
10
AN XY:
716438
show subpopulations
Gnomad4 AFR exome
AF:
0.0000303
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000257
Gnomad4 OTH exome
AF:
0.0000336
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152142
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74322
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000189
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsJul 15, 2021The c.23C>T (p.T8I) alteration is located in exon 2 (coding exon 1) of the KLKB1 gene. This alteration results from a C to T substitution at nucleotide position 23, causing the threonine (T) at amino acid position 8 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.089
BayesDel_addAF
Benign
-0.22
T
BayesDel_noAF
Benign
-0.37
CADD
Benign
3.3
DANN
Benign
0.14
DEOGEN2
Benign
0.068
T;.
Eigen
Benign
-1.2
Eigen_PC
Benign
-1.0
FATHMM_MKL
Benign
0.11
N
LIST_S2
Benign
0.31
T;.
M_CAP
Benign
0.045
D
MetaRNN
Benign
0.098
T;T
MetaSVM
Benign
-0.74
T
MutationTaster
Benign
1.0
N;N
PrimateAI
Benign
0.30
T
PROVEAN
Benign
0.68
N;N
REVEL
Benign
0.13
Sift
Benign
0.77
T;T
Sift4G
Benign
0.26
T;T
Vest4
0.23
MutPred
0.39
Gain of catalytic residue at L13 (P = 0.0337);Gain of catalytic residue at L13 (P = 0.0337);
MVP
0.75
MPC
0.13
ClinPred
0.016
T
GERP RS
1.6
gMVP
0.56

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.21
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.21
Position offset: -23

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs774571178; hg19: chr4-187149372; API