chr4-54699743-A-G

Variant names:

• chr4-54699743-A-G
• rs754400702
• NM_000222.3:c.733A>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 3P and 3B. PM2 PP2 BP4_Moderate BP6

The NM_001385284.1(KIT):​c.733A>G​(p.Thr245Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,824 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T245M) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KIT NM_001385284.1 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.362
• Publications: 3 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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: 4.1411 (above the threshold of 3.09). GenCC associations: The gene is linked to cutaneous mastocytosis, gastrointestinal stromal tumor, mastocytosis, piebaldism.
• BP4: Computational evidence support a benign effect (MetaRNN=0.14407864).
• BP6: Variant 4-54699743-A-G is Benign according to our data. Variant chr4-54699743-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 237281.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001385284.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KIT	NM_000222.3	MANE Select	c.733A>G	p.Thr245Ala	missense	Exon 4 of 21	NP_000213.1
	KIT	NM_001385284.1		c.733A>G	p.Thr245Ala	missense	Exon 4 of 21	NP_001372213.1
	KIT	NM_001385290.1		c.733A>G	p.Thr245Ala	missense	Exon 4 of 21	NP_001372219.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KIT	ENST00000288135.6	TSL:1 MANE Select	c.733A>G	p.Thr245Ala	missense	Exon 4 of 21	ENSP00000288135.6
	KIT	ENST00000412167.7	TSL:1	c.733A>G	p.Thr245Ala	missense	Exon 4 of 21	ENSP00000390987.3
	KIT	ENST00000687109.1		c.733A>G	p.Thr245Ala	missense	Exon 4 of 21	ENSP00000509371.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152142 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251388 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461682 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727138

African (AFR) AF: 0.0000299 AC: 1 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111846

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152142 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74320

African (AFR) AF: 0.0000241 AC: 1 AN: 41442

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5178

South Asian (SAS) AF: 0.00 AC: 0 AN: 4810

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	-	Gastrointestinal stromal tumor (1)
-	-	1	Hereditary cancer-predisposing syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.072
BayesDel_addAF	Benign	-0.48	T
BayesDel_noAF	Benign	-0.75
CADD	Benign	0.33
DANN	Benign	0.18
DEOGEN2	Benign	0.29	T
Eigen	Benign	-1.8
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.097	N
LIST_S2	Benign	0.24	T
M_CAP	Benign	0.0038	T
MetaRNN	Benign	0.14	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.69	N
PhyloP100		0.36
PrimateAI	Benign	0.22	T
PROVEAN	Benign	-1.0	N
REVEL	Benign	0.057
Sift	Benign	0.72	T
Sift4G	Benign	0.76	T
Polyphen		0.0	B
Vest4		0.082
MutPred		0.58		Gain of catalytic residue at T245 (P = 0.0113)
MVP		0.14
MPC		0.44
ClinPred		0.015	T
GERP RS		-2.4
Varity_R		0.12
gMVP		0.83
Mutation Taster		=88/12	polymorphism

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

Other links and lift over

dbSNP: rs754400702; hg19: chr4-55565909;