4-54728031-C-T

Variant names:

Variant summary

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

The NM_000222.3(KIT):c.1900C>T(p.Arg634Trp) variant causes a missense change. The variant allele was found at a frequency of 0.00000958 in 1,461,742 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. R634G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

KIT
NM_000222.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 3.79

Publications

40 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

KIT links:

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 GnomAdExome4 at 14 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KIT	NM_000222.3 link	c.1900C>T	p.Arg634Trp	missense_variant	Exon 13 of 21	ENST00000288135.6	NP_000213.1	P10721-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KIT	ENST00000288135.6 link	c.1900C>T	p.Arg634Trp	missense_variant	Exon 13 of 21	1	NM_000222.3	ENSP00000288135.6		P10721-1

Frequencies

GnomAD3 genomes

AF:

0.00

AC:

AN:

152092

Hom.:

Cov.:

Gnomad AFR

AF:

0.00

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000796

AC:

AN:

251296

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1461742

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727184

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44714

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26128

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000989

AC:

AN:

1111884

Other (OTH)

AF:

0.0000166

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.446

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

152092

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74290

African (AFR)

AF:

0.00

AC:

AN:

41416

American (AMR)

AF:

0.00

AC:

AN:

15264

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68014

Other (OTH)

AF:

0.00

AC:

AN:

2094

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Gastrointestinal stromal tumor

Uncertain:2

Jul 16, 2024

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 tryptophan, which is neutral and slightly polar, at codon 634 of the KIT protein (p.Arg634Trp). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with chronic myelomonocytic leukemia, familial mastocytosis, systemic mastocytosis and/or acral melanoma (PMID: 15790786, 25243845, 28327988, 28520972, 35753512). ClinVar contains an entry for this variant (Variation ID: 409732). 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 affects KIT function (PMID: 15790786). 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. -

Jun 23, 2023

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Acute myeloid leukemia;C0080024:Piebaldism;C0238198:Gastrointestinal stromal tumor;C1136033:Cutaneous mastocytosis;C1336708:Germ cell tumor of testis

Uncertain:1

Jan 19, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome

Uncertain:1

Feb 23, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R634W variant (also known as c.1900C>T), located in coding exon 13 of the KIT gene, results from a C to T substitution at nucleotide position 1900. The arginine at codon 634 is replaced by tryptophan, an amino acid with dissimilar properties. This alteration has been identified in a family with urticaria pigmentosa (Pollard WL et al. Pediatr Dermatol Sep;32:267-70) and in individuals diagnosed with systemic mastocytosis (Astle JM et al. Lab Med, 2017 Aug;48:253-257; Similuk MN et al. J Allergy Clin Immunol, 2022 Oct;150:947-954). This amino acid position is not well 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

0.67

BayesDel_addAF

Uncertain

0.049

BayesDel_noAF

Uncertain

-0.070

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.89

.;D

Eigen

Benign

0.17

Eigen_PC

Benign

0.014

FATHMM_MKL

Benign

0.69

LIST_S2

Uncertain

0.96

D;D

M_CAP

Pathogenic

0.36

MetaRNN

Uncertain

0.70

D;D

MetaSVM

Uncertain

0.075

MutationAssessor

Benign

1.7

.;L

PhyloP100

3.8

PrimateAI

Pathogenic

0.85

PROVEAN

Pathogenic

-6.0

D;D

REVEL

Pathogenic

0.81

Sift

Uncertain

0.0010

D;D

Sift4G

Pathogenic

0.0010

D;D

Polyphen

1.0

D;D

Vest4

0.52

MVP

0.76

MPC

1.3

ClinPred

0.99

GERP RS

0.82

Varity_R

0.88

gMVP

0.80

Mutation Taster

=31/69

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.060

Details are displayed if max score is > 0.2

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

Publications

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4-54728031-C-T

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over