12-25227330-C-T

Variant names:

• chr12-25227330-C-T
• rs1555194026
• NM_033360.4:c.194G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The NM_033360.4(KRAS):​c.194G>A​(p.Ser65Asn) 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S65I) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KRAS NM_033360.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.89
• Publications: 1 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 8 ACMG points.

• PM1: In a hotspot region, there are 22 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 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 chr12-25227330-C-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 438796.Status of the report is reviewed_by_expert_panel, 3 stars.
• 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, 0.767

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KRAS	NM_033360.4	c.194G>A	p.Ser65Asn	missense_variant	Exon 3 of 6	ENST00000256078.10	NP_203524.1
KRAS	NM_004985.5	c.194G>A	p.Ser65Asn	missense_variant	Exon 3 of 5	ENST00000311936.8	NP_004976.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KRAS	ENST00000256078.10	c.194G>A	p.Ser65Asn	missense_variant	Exon 3 of 6	1	NM_033360.4	ENSP00000256078.5
KRAS	ENST00000311936.8	c.194G>A	p.Ser65Asn	missense_variant	Exon 3 of 5	1	NM_004985.5	ENSP00000308495.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Benign	-0.041	T
BayesDel_noAF	Benign	-0.30
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.81	.;D
Eigen	Uncertain	0.63
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.69	T;T
M_CAP	Benign	0.059	D
MetaRNN	Pathogenic	0.77	D;D
MetaSVM	Uncertain	-0.13	T
MutationAssessor	Benign	1.0	L;L
PhyloP100		7.9
PrimateAI	Pathogenic	0.89	D
PROVEAN	Uncertain	-2.7	D;D
REVEL	Uncertain	0.46
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.015	D;D
Polyphen		0.99	D;P
Vest4		0.79
MutPred		0.47		Gain of catalytic residue at M67 (P = 0.0609);Gain of catalytic residue at M67 (P = 0.0609);
MVP		0.95
MPC		2.4
ClinPred		0.96	D
GERP RS		5.8
Varity_R		0.98
gMVP		0.83
Mutation Taster		=0/100	disease causing

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: rs1555194026; hg19: chr12-25380264; COSMIC: COSV55715913;