4-54728096-T-A

Position:

• chr4-54728096-T-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Moderate PP5_Moderate

The NM_000222.3(KIT):​c.1965T>A​(p.Asn655Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: KIT NM_000222.3 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.12

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.935
• PP5: Variant 4-54728096-T-A is Pathogenic according to our data. Variant chr4-54728096-T-A is described in ClinVar as [Pathogenic]. Clinvar id is 375923.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KIT	NM_000222.3	c.1965T>A	p.Asn655Lys	missense_variant	13/21	ENST00000288135.6	NP_000213.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KIT	ENST00000288135.6	c.1965T>A	p.Asn655Lys	missense_variant	13/21	1	NM_000222.3	ENSP00000288135.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Gastrointestinal stromal tumor Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 01, 2022

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 655 of the KIT protein (p.Asn655Lys). For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects KIT function (PMID: 17489795). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 375923). This missense change has been observed in individuals with clinical features of KIT-related conditions (PMID: 17489795, 23106360, 33212994; Invitae). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Uncertain	0.080	D
BayesDel_noAF	Benign	-0.12
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.80	.;D
Eigen	Benign	-0.14
Eigen_PC	Benign	-0.18
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Uncertain	0.95	D;D
M_CAP	Pathogenic	0.44	D
MetaRNN	Pathogenic	0.94	D;D
MetaSVM	Uncertain	-0.055	T
MutationAssessor	Benign	-0.065	.;N
PrimateAI	Pathogenic	0.83	D
PROVEAN	Pathogenic	-5.5	D;D
REVEL	Uncertain	0.59
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.98
MutPred		0.74		.;Gain of sheet (P = 0.0125);
MVP		0.92
MPC		1.4
ClinPred		1.0	D
GERP RS		-0.33
Varity_R		0.97
gMVP		0.92

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: rs1057519708; hg19: chr4-55594262; COSMIC: COSV55390607; COSMIC: COSV55390607;