chr4-54729437-C-T

Position:

• chr4-54729437-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_000222.3(KIT):​c.2093C>T​(p.Ala698Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,416 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. 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. A698E) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KIT NM_000222.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.24

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KIT. . Gene score misZ 2.5806 (greater than the threshold 3.09). Trascript score misZ 4.1549 (greater than threshold 3.09). GenCC has associacion of gene with piebaldism, gastrointestinal stromal tumor, mastocytosis, cutaneous mastocytosis.
• BP4: Computational evidence support a benign effect (MetaRNN=0.13104066).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KIT	NM_000222.3	c.2093C>T	p.Ala698Val	missense_variant	14/21	ENST00000288135.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KIT	ENST00000288135.6	c.2093C>T	p.Ala698Val	missense_variant	14/21	1	NM_000222.3	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250660 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135480

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461416 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726988

Gnomad4 AFR exome AF: 0.0000299

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: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 13, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 05, 2023

The p.A698V variant (also known as c.2093C>T), located in coding exon 14 of the KIT gene, results from a C to T substitution at nucleotide position 2093. The alanine at codon 698 is replaced by valine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. 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	Benign	0.083
BayesDel_addAF	Benign	-0.26	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	18
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.52	.;D
Eigen	Benign	-0.58
Eigen_PC	Benign	-0.55
FATHMM_MKL	Benign	0.74	D
LIST_S2	Benign	0.81	T;T
M_CAP	Benign	0.029	D
MetaRNN	Benign	0.13	T;T
MetaSVM	Benign	-0.71	T
MutationAssessor	Benign	0.62	.;N
MutationTaster	Benign	0.80	N;N
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-1.4	N;N
REVEL	Benign	0.090
Sift	Benign	0.061	T;D
Sift4G	Benign	0.22	T;T
Polyphen		0.26	B;B
Vest4		0.16
MutPred		0.36		.;Gain of glycosylation at Y703 (P = 0.0278);
MVP		0.75
MPC		0.48
ClinPred		0.079	T
GERP RS		1.1
Varity_R		0.081
gMVP		0.65

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

Other links and lift over

dbSNP: rs780329057; hg19: chr4-55595603;