4-54728031-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP2

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:3

Conservation

PhyloP100: 3.79

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PP2

Missense variant where missense usually causes diseases, KIT

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KIT	NM_000222.3 linkuse as main transcript	c.1900C>T	p.Arg634Trp	missense_variant	13/21	ENST00000288135.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KIT	ENST00000288135.6 linkuse as main transcript	c.1900C>T	p.Arg634Trp	missense_variant	13/21	1	NM_000222.3	P4	P10721-1

Frequencies

GnomAD3 genomes

AF:

0.00

AC:

AN:

152092

Hom.:

Cov.:

FAILED QC

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

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251296

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135808

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 SAS exome

AF:

0.0000327

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

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000989

Gnomad4 OTH exome

AF:

0.0000166

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

Gnomad4 AFR

AF:

0.00

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:

0.00

Gnomad4 OTH

AF:

0.00

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:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Gastrointestinal stromal tumor

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Dec 31, 2023	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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Jun 23, 2023	- -

Hereditary cancer-predisposing syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 23, 2024

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

Dann

Uncertain

1.0

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

MutationTaster

Benign

0.96

N;N

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

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

LitVar

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

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over