rs774405431

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP2BS2

The NM_000222.3(KIT):​c.2683G>A​(p.Ala895Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000167 in 1,613,772 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A895S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

KIT
NM_000222.3 missense

Scores

1
12
6

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 4.74

Publications

14 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: Likely_benign. The variant received -3 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.
BS2
High AC in GnomAd4 at 5 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KITNM_000222.3 linkc.2683G>A p.Ala895Thr missense_variant Exon 19 of 21 ENST00000288135.6 NP_000213.1 P10721-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KITENST00000288135.6 linkc.2683G>A p.Ala895Thr missense_variant Exon 19 of 21 1 NM_000222.3 ENSP00000288135.6 P10721-1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152136
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
250880
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.0000353
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1461636
Hom.:
0
Cov.:
32
AF XY:
0.0000193
AC XY:
14
AN XY:
727130
show subpopulations
African (AFR)
AF:
0.000179
AC:
6
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.0000374
AC:
2
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000126
AC:
14
AN:
1111794
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.486
Heterozygous variant carriers
0
2
3
5
6
8
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
AF:
0.0000329
AC:
5
AN:
152136
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74314
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41434
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5172
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.565
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000193
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Gastrointestinal stromal tumor Uncertain:2
Feb 02, 2024
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 20, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 895 of the KIT protein (p.Ala895Thr). This variant is present in population databases (rs774405431, gnomAD 0.008%). This variant has not been reported in the literature in individuals affected with KIT-related conditions. ClinVar contains an entry for this variant (Variation ID: 409723). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

KIT-related disorder Uncertain:1
Oct 18, 2023
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The KIT c.2683G>A variant is predicted to result in the amino acid substitution p.Ala895Thr. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0080% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/4-55602973-G-A). It is interpreted as uncertain in the ClinVar database (https://www.ncbi.nlm.nih.gov/clinvar/variation/409723/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not provided Uncertain:1
Jul 09, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 32608199, 23890154) -

Hereditary cancer-predisposing syndrome Uncertain:1
Nov 06, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A895T variant (also known as c.2683G>A), located in coding exon 19 of the KIT gene, results from a G to A substitution at nucleotide position 2683. The alanine at codon 895 is replaced by threonine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.66
BayesDel_addAF
Benign
-0.061
T
BayesDel_noAF
Benign
-0.090
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.78
.;D
Eigen
Benign
0.13
Eigen_PC
Benign
0.087
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Uncertain
0.87
D;D
M_CAP
Uncertain
0.086
D
MetaRNN
Uncertain
0.63
D;D
MetaSVM
Uncertain
-0.20
T
MutationAssessor
Benign
0.76
.;N
PhyloP100
4.7
PrimateAI
Uncertain
0.60
T
PROVEAN
Uncertain
-3.1
D;D
REVEL
Uncertain
0.50
Sift
Uncertain
0.0020
D;D
Sift4G
Uncertain
0.0050
D;D
Polyphen
1.0
D;D
Vest4
0.51
MVP
0.88
MPC
1.3
ClinPred
0.57
D
GERP RS
4.6
Varity_R
0.60
gMVP
0.81
Mutation Taster
=80/20
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs774405431; hg19: chr4-55602973; COSMIC: COSV55394257; COSMIC: COSV55394257; API