NM_033360.4:c.182A>C

Variant names:

• chr12-25227342-T-G
• rs121913240
• NM_033360.4:c.182A>C

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate

The NM_033360.4(KRAS):​c.182A>C​(p.Gln61Pro) 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. 13/22 in silico tools predict a damaging 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. Q61H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0 (0 hom., cov: 32)
  • Failed GnomAD Quality Control
• Consequence: KRAS NM_033360.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.00
• Publications: 628 publications found

Genes affected

KRAS (HGNC:6407): (KRAS proto-oncogene, GTPase) This gene, a Kirsten ras oncogene homolog from the mammalian ras gene family, encodes a protein that is a member of the small GTPase superfamily. A single amino acid substitution is responsible for an activating mutation. The transforming protein that results is implicated in various malignancies, including lung adenocarcinoma, mucinous adenoma, ductal carcinoma of the pancreas and colorectal carcinoma. Alternative splicing leads to variants encoding two isoforms that differ in the C-terminal region. [provided by RefSeq, Jul 2008]

KRAS Gene-Disease associations (from GenCC):

• cardiofaciocutaneous syndrome 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, Ambry Genetics, PanelApp Australia
• Noonan syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Noonan syndrome 3

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, PanelApp Australia, Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• cardiofaciocutaneous syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen
• linear nevus sebaceous syndrome

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Costello syndrome

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 14 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_033360.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-25227341-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 177881.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 65 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 2.3177 (below the threshold of 3.09). Trascript score misZ: 2.7433 (below the threshold of 3.09). GenCC associations: The gene is linked to cardiofaciocutaneous syndrome, cardiofaciocutaneous syndrome 2, Noonan syndrome 3, Noonan syndrome, Costello syndrome, linear nevus sebaceous syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.878

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_033360.4. 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
	KRAS	NM_033360.4	MANE Plus Clinical	c.182A>C	p.Gln61Pro	missense	Exon 3 of 6	NP_203524.1
	KRAS	NM_004985.5	MANE Select	c.182A>C	p.Gln61Pro	missense	Exon 3 of 5	NP_004976.2
	KRAS	NM_001369786.1		c.182A>C	p.Gln61Pro	missense	Exon 3 of 6	NP_001356715.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KRAS	ENST00000256078.10	TSL:1 MANE Plus Clinical	c.182A>C	p.Gln61Pro	missense	Exon 3 of 6	ENSP00000256078.5
	KRAS	ENST00000311936.8	TSL:1 MANE Select	c.182A>C	p.Gln61Pro	missense	Exon 3 of 5	ENSP00000308495.3
	KRAS	ENST00000685328.1		c.182A>C	p.Gln61Pro	missense	Exon 3 of 5	ENSP00000508921.1

Frequencies

GnomAD3 genomes AF: 0.00 AC: 0 AN: 152176 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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

GnomAD4 exome Cov.: 31

GnomAD4 genome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 152176 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74356

African (AFR) AF: 0.00 AC: 0 AN: 41438

American (AMR) AF: 0.00 AC: 0 AN: 15276

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5204

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2088

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

RASopathy Uncertain:1

Jul 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine, which is neutral and polar, with proline, which is neutral and non-polar, at codon 61 of the KRAS protein (p.Gln61Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with undergoing clinical exome sequencing (PMID: 27848944). ClinVar contains an entry for this variant (Variation ID: 375966). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt KRAS protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects KRAS function (PMID: 34117033, 35944066). 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.91	D
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	3.5	M
PhyloP100		8.0
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-5.4	D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0030	D
Polyphen		0.99	D
Vest4		0.88
MutPred		0.66		Gain of catalytic residue at A59 (P = 0)
MVP		0.97
MPC		3.0
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.99
gMVP		0.98
Mutation Taster		=1/99	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs121913240; hg19: chr12-25380276; COSMIC: COSV55508574; COSMIC: COSV55508574;