NM_033360.4:c.261delT

Variant names:

• chr12-25227262-TA-T
• rs397517038
• NM_033360.4:c.261delT

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_033360.4(KRAS):​c.261delT​(p.Lys88AsnfsTer26) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. T87T) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay. The gene KRAS is included in the ClinGen Criteria Specification Registry.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KRAS NM_033360.4 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.48
• 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), Ambry Genetics, G2P, Genomics England PanelApp
• Noonan syndrome

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

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

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• Noonan syndrome-like disorder with loose anagen hair

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Specifications for KRAS are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KRAS	NM_033360.4	MANE Plus Clinical	c.261delT	p.Lys88AsnfsTer26	frameshift	Exon 3 of 6	NP_203524.1	P01116-1
	KRAS	NM_004985.5	MANE Select	c.261delT	p.Lys88AsnfsTer26	frameshift	Exon 3 of 5	NP_004976.2
	KRAS	NM_001369786.1		c.261delT	p.Lys88AsnfsTer26	frameshift	Exon 3 of 6	NP_001356715.1	P01116-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KRAS	ENST00000256078.10	TSL:1 MANE Plus Clinical	c.261delT	p.Lys88AsnfsTer26	frameshift	Exon 3 of 6	ENSP00000256078.5	P01116-1
	KRAS	ENST00000311936.8	TSL:1 MANE Select	c.261delT	p.Lys88AsnfsTer26	frameshift	Exon 3 of 5	ENSP00000308495.3	P01116-2
	KRAS	ENST00000685328.1		c.261delT	p.Lys88AsnfsTer26	frameshift	Exon 3 of 5	ENSP00000508921.1	P01116-2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.5

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs397517038;

hg19: chr12-25380196;