rs754826149

chr4-54731912-G-Achr4-54731912-G-Cchr4-54731912-G-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.2275G>A(p.Asp759Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,510 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. D759Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: KIT NM_000222.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.74

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 where missense usually causes diseases, KIT
• BP4: Computational evidence support a benign effect (MetaRNN=0.2269749).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KIT	NM_000222.3	c.2275G>A	p.Asp759Asn	missense_variant	16/21	ENST00000288135.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KIT	ENST00000288135.6	c.2275G>A	p.Asp759Asn	missense_variant	16/21	1	NM_000222.3	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251368 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135850

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461510 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727062

Gnomad4 AFR exome AF: 0.00

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Gastrointestinal stromal tumor Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	May 18, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Jan 18, 2024	This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 759 of the KIT protein (p.Asp759Asn). This variant is present in population databases (rs754826149, gnomAD 0.003%). 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: 572804). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.23
BayesDel_addAF	Benign	-0.037	T
BayesDel_noAF	Benign	-0.19
Cadd	Uncertain	25
Dann	Uncertain	1.0
Eigen	Benign	0.15
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Benign	0.062	D
MetaRNN	Benign	0.23	T;T
MetaSVM	Uncertain	0.090	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.64	T
PROVEAN	Benign	-2.3	N;N
REVEL	Uncertain	0.36
Sift	Uncertain	0.013	D;D
Sift4G	Uncertain	0.032	D;D
Polyphen		0.023	B;P
Vest4		0.31
MutPred		0.43		.;Gain of catalytic residue at D759 (P = 0.0297);
MVP		0.83
MPC		1.0
ClinPred		0.58	D
GERP RS		6.0
Varity_R		0.31
gMVP		0.56

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: rs754826149; hg19: chr4-55598078; COSMIC: COSV99855672;