rs776681643

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PP2PP3BS1_SupportingBS2

The NM_000222.3(KIT):​c.2663G>A​(p.Arg888Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000905 in 1,613,960 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000094 ( 0 hom. )

Consequence

KIT
NM_000222.3 missense

Scores

5
7
7

Clinical Significance

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

Conservation

PhyloP100: 6.73
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -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 piebaldism, gastrointestinal stromal tumor, mastocytosis, cutaneous mastocytosis.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.832
BS1
Variant frequency is greater than expected in population nfe. gnomad4_exome allele frequency = 0.0000944 (138/1461820) while in subpopulation NFE AF= 0.000118 (131/1111956). AF 95% confidence interval is 0.000101. There are 0 homozygotes in gnomad4_exome. There are 70 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High AC in GnomAd4 at 8 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KITNM_000222.3 linkc.2663G>A p.Arg888Gln 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.2663G>A p.Arg888Gln missense_variant Exon 19 of 21 1 NM_000222.3 ENSP00000288135.6 P10721-1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152140
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.0000882
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.0000279
AC:
7
AN:
251078
Hom.:
0
AF XY:
0.0000295
AC XY:
4
AN XY:
135698
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000529
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000944
AC:
138
AN:
1461820
Hom.:
0
Cov.:
32
AF XY:
0.0000963
AC XY:
70
AN XY:
727210
show subpopulations
Gnomad4 AFR exome
AF:
0.0000597
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:
0.0000374
Gnomad4 NFE exome
AF:
0.000118
Gnomad4 OTH exome
AF:
0.0000497
GnomAD4 genome
AF:
0.0000526
AC:
8
AN:
152140
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74328
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000882
Gnomad4 OTH
AF:
0.000478
Alfa
AF:
0.000113
Hom.:
0
Bravo
AF:
0.0000529
ExAC
AF:
0.0000494
AC:
6
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

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

Submissions by phenotype

Gastrointestinal stromal tumor Uncertain:2
Jan 19, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 888 of the KIT protein (p.Arg888Gln). This variant is present in population databases (rs776681643, gnomAD 0.006%). This missense change has been observed in individual(s) with melanoma, bone marrow failure, and colorectal cancer (PMID: 23020152, 29146883, 29625052, 36451132). ClinVar contains an entry for this variant (Variation ID: 409758). 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. Experimental studies have shown that this missense change does not substantially affect KIT function (PMID: 23020152). 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. -

Oct 30, 2023
Baylor Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Uncertain:1
May 20, 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; Observed in individuals with a personal or family history including colon cancer and bone marrow failure (Bluteau et al., 2018; Huang et al., 2018); This variant is associated with the following publications: (PMID: 29146883, 29625052) -

Acute myeloid leukemia;C0080024:Piebaldism;C0238198:Gastrointestinal stromal tumor;C1136033:Cutaneous mastocytosis;C1336708:Germ cell tumor of testis Uncertain:1
Apr 22, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Benign:1
Dec 16, 2024
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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.48
BayesDel_addAF
Benign
0.0044
T
BayesDel_noAF
Uncertain
-0.060
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.54
.;D
Eigen
Pathogenic
0.73
Eigen_PC
Pathogenic
0.70
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.96
D;D
M_CAP
Benign
0.081
D
MetaRNN
Pathogenic
0.83
D;D
MetaSVM
Uncertain
0.40
D
MutationAssessor
Benign
1.8
.;L
PrimateAI
Uncertain
0.67
T
PROVEAN
Benign
-1.1
N;N
REVEL
Uncertain
0.55
Sift
Benign
0.43
T;T
Sift4G
Benign
0.62
T;T
Polyphen
1.0
D;D
Vest4
0.94
MVP
0.89
MPC
1.4
ClinPred
0.59
D
GERP RS
5.6
Varity_R
0.43
gMVP
0.87

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

LitVar

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

Other links and lift over

dbSNP: rs776681643; hg19: chr4-55602953; COSMIC: COSV55391670; COSMIC: COSV55391670; API