4-54698449-C-T

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 1P and 9B. PP2BP6BS1BS2

The NM_000222.3(KIT):​c.503C>T​(p.Ala168Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000126 in 1,614,148 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A168G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00060 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000076 ( 0 hom. )

Consequence

KIT
NM_000222.3 missense

Scores

6
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:4O:1

Conservation

PhyloP100: 2.69

Publications

7 publications found
Variant links:
Genes affected
KIT (HGNC:6342): (KIT proto-oncogene, receptor tyrosine kinase) This gene encodes a receptor tyrosine kinase. This gene was initially identified as a homolog of the feline sarcoma viral oncogene v-kit and is often referred to as proto-oncogene c-Kit. The canonical form of this glycosylated transmembrane protein has an N-terminal extracellular region with five immunoglobulin-like domains, a transmembrane region, and an intracellular tyrosine kinase domain at the C-terminus. Upon activation by its cytokine ligand, stem cell factor (SCF), this protein phosphorylates multiple intracellular proteins that play a role in in the proliferation, differentiation, migration and apoptosis of many cell types and thereby plays an important role in hematopoiesis, stem cell maintenance, gametogenesis, melanogenesis, and in mast cell development, migration and function. This protein can be a membrane-bound or soluble protein. Mutations in this gene are associated with gastrointestinal stromal tumors, mast cell disease, acute myelogenous leukemia, and piebaldism. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2020]
KIT Gene-Disease associations (from GenCC):
  • gastrointestinal stromal tumor
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Ambry Genetics
  • piebaldism
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
  • cutaneous mastocytosis
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • mastocytosis
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -8 ACMG points.

PP2
Missense variant in the KIT gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 54 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: 2.5806 (below the threshold of 3.09). Trascript score misZ: 4.1549 (above the threshold of 3.09). GenCC associations: The gene is linked to cutaneous mastocytosis, gastrointestinal stromal tumor, mastocytosis, piebaldism.
BP6
Variant 4-54698449-C-T is Benign according to our data. Variant chr4-54698449-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 134628.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000604 (92/152272) while in subpopulation AFR AF = 0.00212 (88/41546). AF 95% confidence interval is 0.00176. There are 0 homozygotes in GnomAd4. There are 38 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High AC in GnomAd4 at 92 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KITNM_000222.3 linkc.503C>T p.Ala168Val missense_variant Exon 3 of 21 ENST00000288135.6 NP_000213.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KITENST00000288135.6 linkc.503C>T p.Ala168Val missense_variant Exon 3 of 21 1 NM_000222.3 ENSP00000288135.6

Frequencies

GnomAD3 genomes
AF:
0.000592
AC:
90
AN:
152154
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00208
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000262
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000151
AC:
38
AN:
251264
AF XY:
0.0000810
show subpopulations
Gnomad AFR exome
AF:
0.00203
Gnomad AMR exome
AF:
0.0000868
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000759
AC:
111
AN:
1461876
Hom.:
0
Cov.:
32
AF XY:
0.0000798
AC XY:
58
AN XY:
727234
show subpopulations
African (AFR)
AF:
0.00197
AC:
66
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000144
AC:
16
AN:
1112000
Other (OTH)
AF:
0.000364
AC:
22
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
7
15
22
30
37
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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
AF:
0.000604
AC:
92
AN:
152272
Hom.:
0
Cov.:
33
AF XY:
0.000510
AC XY:
38
AN XY:
74444
show subpopulations
African (AFR)
AF:
0.00212
AC:
88
AN:
41546
American (AMR)
AF:
0.000261
AC:
4
AN:
15302
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5164
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.503
Heterozygous variant carriers
0
5
10
14
19
24
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000229
Hom.:
0
Bravo
AF:
0.000684
ESP6500AA
AF:
0.00204
AC:
9
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000198
AC:
24

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:4Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Jun 10, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; In silico analysis, which includes splice predictors and evolutionary conservation, suggests this variant may impact gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown. -

Sep 28, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The KIT c.503C>T; p.Ala168Val variant (rs149092990), to our knowledge, is not reported in the medical literature associated with familial gastrointestinal stromal tumors but is reported in ClinVar (Variation ID: 134628). This variant is found in the African/African-American population with an allele frequency of 0.2% (52/24966 alleles) in the Genome Aggregation Database. Computational analyses (Alamut Visual Plus v.1.5.1) predict that this variant may impact splicing by creating a novel cryptic donor splice site. However, the splicing impact of this variant would need to be determined by functional studies. While the high population frequency suggests that this is likely a benign variant, given the lack of clinical and functional data, the significance of this variant is uncertain at this time. -

Gastrointestinal stromal tumor Benign:2
Jul 07, 2023
KCCC/NGS Laboratory, Kuwait Cancer Control Center
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 22, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

KIT-related disorder Benign:1
Nov 15, 2021
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Hereditary cancer-predisposing syndrome Benign:1
May 15, 2019
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

not specified Other:1
Sep 19, 2013
ITMI
Significance:not provided
Review Status:no classification provided
Collection Method:reference population

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.33
T
BayesDel_noAF
Benign
-0.25
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.36
.;T
Eigen
Uncertain
0.24
Eigen_PC
Uncertain
0.27
FATHMM_MKL
Uncertain
0.81
D
LIST_S2
Uncertain
0.94
D;D
M_CAP
Benign
0.052
D
MetaRNN
Benign
0.018
T;T
MetaSVM
Benign
-0.51
T
MutationAssessor
Uncertain
2.2
M;M
PhyloP100
2.7
PrimateAI
Benign
0.34
T
PROVEAN
Benign
-1.6
N;N
REVEL
Benign
0.24
Sift
Benign
0.22
T;T
Sift4G
Benign
0.21
T;T
Polyphen
0.96
D;D
Vest4
0.28
MVP
0.85
MPC
0.56
ClinPred
0.025
T
GERP RS
4.8
Varity_R
0.095
gMVP
0.83
Mutation Taster
=80/20
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.28
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.28
Position offset: -2

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

Publications

Other links and lift over

dbSNP: rs149092990; hg19: chr4-55564615; COSMIC: COSV55389252; COSMIC: COSV55389252; API