4-54658023-C-T

Variant names:

• chr4-54658023-C-T
• rs755780019
• NM_000222.3:c.9C>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP6

The NM_001385284.1(KIT):​c.9C>T​(p.Gly3Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,572 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. G3G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KIT NM_001385284.1 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 2.22
• 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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 4-54658023-C-T is Benign according to our data. Variant chr4-54658023-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 581848.

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.9C>T	p.Gly3Gly	synonymous	Exon 1 of 21	NP_000213.1
	KIT	NM_001385284.1		c.9C>T	p.Gly3Gly	synonymous	Exon 1 of 21	NP_001372213.1
	KIT	NM_001385290.1		c.9C>T	p.Gly3Gly	synonymous	Exon 1 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.9C>T	p.Gly3Gly	synonymous	Exon 1 of 21	ENSP00000288135.6
	KIT	ENST00000412167.7	TSL:1	c.9C>T	p.Gly3Gly	synonymous	Exon 1 of 21	ENSP00000390987.3
	KIT	ENST00000687109.1		c.9C>T	p.Gly3Gly	synonymous	Exon 1 of 21	ENSP00000509371.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000799 AC: 2 AN: 250384 AF XY: 0.00000737

Gnomad AFR exome AF: 0.0000619

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 1461572 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727106

African (AFR) AF: 0.0000299 AC: 1 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53332

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111834

Other (OTH) AF: 0.00 AC: 0 AN: 60380

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

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)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.23
CADD	Benign	22
DANN	Uncertain	0.98
PhyloP100		2.2
PromoterAI		0.013	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.47		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.47		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs755780019; hg19: chr4-55524190;