NM_000226.4:c.482A>G

Variant names:

• chr17-41571511-T-C
• rs56707768
• NM_000226.4:c.482A>G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000226.4(KRT9):​c.482A>G​(p.Asn161Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N161H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KRT9 NM_000226.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4 O:1
• Conservation: PhyloP100: 3.47

Genes affected

KRT9 (HGNC:6447): (keratin 9) This gene encodes the type I keratin 9, an intermediate filament chain expressed only in the terminally differentiated epidermis of palms and soles. Mutations in this gene cause epidermolytic palmoplantar keratoderma. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a region_of_interest Coil 1A (size 35) in uniprot entity K1C9_HUMAN there are 22 pathogenic changes around while only 0 benign (100%) in NM_000226.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 17-41571511-T-C is Pathogenic according to our data. Variant chr17-41571511-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 3003.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-41571511-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KRT9	NM_000226.4	c.482A>G	p.Asn161Ser	missense_variant	Exon 1 of 8	ENST00000246662.9	NP_000217.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KRT9	ENST00000246662.9	c.482A>G	p.Asn161Ser	missense_variant	Exon 1 of 8	1	NM_000226.4	ENSP00000246662.4
KRT9	ENST00000588431.1	c.-189-29A>G		intron_variant	Intron 1 of 8	1		ENSP00000467932.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461882 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727240

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2 Other:1

Sep 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 161 of the KRT9 protein (p.Asn161Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with epidermolytic palmoplantar keratoderma (PMID: 7523529, 30666268). It has also been observed to segregate with disease in related individuals. This variant is also known as p.Asn160Ser. ClinVar contains an entry for this variant (Variation ID: 3003). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt KRT9 protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -

May 05, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Located within the helix initiation motif within the 1A region of the rod domain, which is a well-known mutation hotspot intolerant to change; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 7523529, 29444371, 30666268, 33914963, 24510562, 18573708) -

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Epithelial Biology; Institute of Medical Biology, Singapore

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Epidermolytic palmoplantar keratoderma, 1 Pathogenic:2

Jul 30, 2003

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

-

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PP3+PM1+PS4_Moderate+PP1_Strong+PP4 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.79
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.070
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D
Eigen	Uncertain	0.42
Eigen_PC	Benign	0.21
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.83	T
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	1.0	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.8	H
PrimateAI	Benign	0.43	T
PROVEAN	Pathogenic	-4.7	D
REVEL	Pathogenic	0.77
Sift	Pathogenic	0.0	D
Sift4G	Benign	0.066	T
Polyphen		1.0	D
Vest4		0.92
MutPred		0.99		Gain of phosphorylation at N161 (P = 0.0534);
MVP		0.99
MPC		0.30
ClinPred		0.97	D
GERP RS		4.6
Varity_R		0.80
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs56707768; hg19: chr17-39727763;