NM_006121.4:c.1864_1865delGG

Variant names:

• chr12-52675262-ACC-A
• NM_006121.4:c.1864_1865delGG

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_006121.4(KRT1):​c.1864_1865delGG​(p.Gly622CysfsTer31) 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 (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: KRT1 NM_006121.4 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.99

Genes affected

KRT1 (HGNC:6412): (keratin 1) The protein encoded by this gene is a member of the keratin gene family. The type II cytokeratins consist of basic or neutral proteins which are arranged in pairs of heterotypic keratin chains coexpressed during differentiation of simple and stratified epithelial tissues. This type II cytokeratin is specifically expressed in the spinous and granular layers of the epidermis with family member KRT10 and mutations in these genes have been associated with bullous congenital ichthyosiform erythroderma. The type II cytokeratins are clustered in a region of chromosome 12q12-q13. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0367 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KRT1	NM_006121.4	c.1864_1865delGG	p.Gly622CysfsTer31	frameshift_variant	Exon 9 of 9	ENST00000252244.3	NP_006112.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KRT1	ENST00000252244.3	c.1864_1865delGG	p.Gly622CysfsTer31	frameshift_variant	Exon 9 of 9	1	NM_006121.4	ENSP00000252244.3

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Jan 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change results in a frameshift in the KRT1 gene (p.Gly622Cysfs*31). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 23 amino acid(s) of the KRT1 protein and extend the protein by 7 additional amino acid residues. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with KRT1-related conditions. This variant results in an extension of the KRT1 protein. Other variant(s) that result in a similarly extended protein product (p.Val623Cysfs*31) have been determined to be pathogenic (PMID: 25774499). This suggests that these extensions are likely to be disease-causing. 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 v4.3

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-53069046;