4-54728026-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP2

The NM_000222.3(KIT):​c.1895C>T​(p.Thr632Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,246 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. T632A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

KIT
NM_000222.3 missense

Scores

2
14
3

Clinical Significance

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

Conservation

PhyloP100: 4.91

Publications

1 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: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KITNM_000222.3 linkc.1895C>T p.Thr632Ile missense_variant Exon 13 of 21 ENST00000288135.6 NP_000213.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KITENST00000288135.6 linkc.1895C>T p.Thr632Ile missense_variant Exon 13 of 21 1 NM_000222.3 ENSP00000288135.6

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152128
Hom.:
0
Cov.:
32
show subpopulations
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
32
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152246
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74438
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41546
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

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
Dec 23, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 632 of the KIT protein (p.Thr632Ile). This variant is not present in population databases (gnomAD no frequency). 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: 458897). 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. -

May 12, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

KIT-related disorder Uncertain:1
Jan 29, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The KIT c.1895C>T variant is predicted to result in the amino acid substitution p.Thr632Ile. To our knowledge, this variant has not been reported in the literature or in a large population database, indicating this variant is rare. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Hereditary cancer-predisposing syndrome Uncertain:1
Nov 29, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1895C>T (p.T632I) alteration is located in exon 13 (coding exon 13) of the KIT gene. This alteration results from a C to T substitution at nucleotide position 1895, causing the threonine (T) at amino acid position 632 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.87
BayesDel_addAF
Uncertain
0.019
T
BayesDel_noAF
Benign
-0.21
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.77
.;D
Eigen
Uncertain
0.34
Eigen_PC
Uncertain
0.26
FATHMM_MKL
Uncertain
0.89
D
LIST_S2
Uncertain
0.91
D;D
M_CAP
Uncertain
0.12
D
MetaRNN
Uncertain
0.50
T;T
MetaSVM
Uncertain
0.32
D
MutationAssessor
Benign
0.57
.;N
PhyloP100
4.9
PrimateAI
Pathogenic
0.89
D
PROVEAN
Uncertain
-4.2
D;D
REVEL
Uncertain
0.43
Sift
Uncertain
0.014
D;D
Sift4G
Uncertain
0.033
D;D
Polyphen
1.0
D;D
Vest4
0.46
MutPred
0.44
.;Gain of glycosylation at T632 (P = 0.0129);
MVP
0.80
MPC
1.3
ClinPred
1.0
D
GERP RS
5.2
Varity_R
0.72
gMVP
0.73
Mutation Taster
=50/50

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: rs1553891944; hg19: chr4-55594192; COSMIC: COSV55409179; COSMIC: COSV55409179; API