chr4-54723696-G-C

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.1344G>C(p.Gln448His) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000504 in 1,585,994 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. Q448Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000042 ( 0 hom. )

Consequence

KIT
NM_000222.3 missense, splice_region

Scores

Splicing: ADA: 0.1319

Clinical Significance

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

Conservation

PhyloP100: 0.979

Publications

0 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 6 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000222.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KIT	NM_000222.3	MANE Select	c.1344G>C	p.Gln448His	missense splice_region	Exon 8 of 21	NP_000213.1
KIT	NM_001385284.1		c.1347G>C	p.Gln449His	missense splice_region	Exon 8 of 21	NP_001372213.1
KIT	NM_001385290.1		c.1347G>C	p.Gln449His	missense splice_region	Exon 8 of 21	NP_001372219.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KIT	ENST00000288135.6	TSL:1 MANE Select	c.1344G>C	p.Gln448His	missense splice_region	Exon 8 of 21	ENSP00000288135.6
KIT	ENST00000412167.7	TSL:1	c.1347G>C	p.Gln449His	missense splice_region	Exon 8 of 21	ENSP00000390987.3
KIT	ENST00000687109.1		c.1347G>C	p.Gln449His	missense splice_region	Exon 8 of 21	ENSP00000509371.1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

251366

AF XY:

0.0000294

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000579

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000419

AC:

AN:

1433650

Hom.:

Cov.:

AF XY:

0.00000699

AC XY:

AN XY:

715098

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32888

American (AMR)

AF:

0.0000224

AC:

AN:

44672

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25968

East Asian (EAS)

AF:

0.00

AC:

AN:

39578

South Asian (SAS)

AF:

0.00

AC:

AN:

85692

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53398

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5512

European-Non Finnish (NFE)

AF:

0.00000460

AC:

AN:

1086568

Other (OTH)

AF:

0.00

AC:

AN:

59374

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.433

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000131

AC:

AN:

152344

Hom.:

Cov.:

AF XY:

0.0000268

AC XY:

AN XY:

74492

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41576

American (AMR)

AF:

0.0000653

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.00

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

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 18, 2023

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Oct 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 448 of the KIT protein (p.Gln448His). This variant is present in population databases (rs542718349, gnomAD 0.006%). 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: 458867). 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.

Hereditary cancer-predisposing syndrome

Uncertain:1

Sep 27, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Q448H variant (also known as c.1344G>C), located in coding exon 8 of the KIT gene, results from a G to C substitution at nucleotide position 1344. The glutamine at codon 448 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is conserved. 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.

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

Uncertain:1

Mar 28, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Benign

-0.067

BayesDel_noAF

Benign

-0.16

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.38

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.46

FATHMM_MKL

Uncertain

0.80

LIST_S2

Benign

0.82

M_CAP

Uncertain

0.11

MetaRNN

Uncertain

0.49

MetaSVM

Uncertain

0.22

MutationAssessor

Uncertain

2.6

PhyloP100

0.98

PrimateAI

Benign

0.42

PROVEAN

Benign

-2.1

REVEL

Uncertain

0.46

Sift

Benign

0.032

Sift4G

Benign

0.11

Polyphen

1.0

Vest4

0.52

MutPred

0.33

Gain of glycosylation at T446 (P = 0.0737)

MVP

0.87

MPC

1.2

ClinPred

0.68

GERP RS

4.3

Varity_R

0.38

gMVP

0.81

Mutation Taster

=56/44

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.13

dbscSNV1_RF

Benign

0.46

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over