4-54733154-G-T

Position:

• chr4-54733154-G-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000222.3(KIT):​c.2446G>T​(p.Asp816Tyr) variant causes a missense change involving the alteration of a 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 Likely pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D816I) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KIT NM_000222.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic no assertion criteria provided P:6
• Conservation: PhyloP100: 9.89

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 Pathogenic. Variant got 12 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000222.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr4-54733154-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 13863.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• 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, 0.969
• PP5: Variant 4-54733154-G-T is Pathogenic according to our data. Variant chr4-54733154-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 13860.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KIT	NM_000222.3	c.2446G>T	p.Asp816Tyr	missense_variant	17/21	ENST00000288135.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KIT	ENST00000288135.6	c.2446G>T	p.Asp816Tyr	missense_variant	17/21	1	NM_000222.3	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: no assertion criteria provided

Submissions by phenotype

Acute myeloid leukemia Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Jul 15, 1998	- -
Pathogenic, no assertion criteria provided	literature only	Database of Curated Mutations (DoCM)	Oct 02, 2014	- -

MASTOCYTOSIS, CUTANEOUS AND SYSTEMIC, SOMATIC Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jul 15, 1998

- -

Hematologic neoplasm Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

May 13, 2016

- -

Melanoma Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

Oct 02, 2014

- -

Gastrointestinal stromal tumor Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

Jul 14, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.81	.;D
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.87	D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Uncertain	0.32	D
MutationAssessor	Benign	0.46	.;N
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-7.6	D;D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	D;D
Vest4		0.96
MutPred		0.85		.;Gain of MoRF binding (P = 0.0752);
MVP		0.98
MPC		1.4
ClinPred		0.99	D
GERP RS		5.6
Varity_R		0.98
gMVP		0.92

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs121913506; hg19: chr4-55599320; COSMIC: COSV55387240;