rs28928894

Positions:

• chr17-41612327-A-C
• chr17-41612327-A-G
• chr17-41612327-A-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_005557.4(KRT16):​c.362T>G​(p.Met121Arg) 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. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M121K) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KRT16 NM_005557.4 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.20

Genes affected

KRT16 (HGNC:6423): (keratin 16) The protein encoded by this gene is a member of the keratin gene family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. Most of the type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains and are clustered in a region of chromosome 17q12-q21. This keratin has been coexpressed with keratin 14 in a number of epithelial tissues, including esophagus, tongue, and hair follicles. Mutations in this gene are associated with type 1 pachyonychia congenita, non-epidermolytic palmoplantar keratoderma and unilateral palmoplantar verrucous nevus. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 uncertain in NM_005557.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-41612327-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 14608.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.986
• PP5: Variant 17-41612327-A-C is Pathogenic according to our data. Variant chr17-41612327-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 419351.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KRT16	NM_005557.4	c.362T>G	p.Met121Arg	missense_variant	1/8	ENST00000301653.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KRT16	ENST00000301653.9	c.362T>G	p.Met121Arg	missense_variant	1/8	1	NM_005557.4	P1
KRT16	ENST00000593067.1	c.-312-41T>G		intron_variant		3
KRT16	ENST00000588319.1	n.439T>G		non_coding_transcript_exon_variant	1/1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Dec 31, 2015

The M121R variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. Missense variants in this residue (M121K, M121T) and in nearby residues (Q122P, L124R, L124P, L124H, N125D, N125S, R127C, R127G, R127S, R127P, R127H, L128P, L128Q) have been reported in the Human Gene Mutation Database in association with pachyonychia congenita and non-epidermolytic palmoplantar keratoderma (Stenson et al., 2014), supporting the functional importance of this region of the protein. Therefore, based on the currently available information, we interpret M121R as a pathogenic variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	31
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.78	D
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.82	T
M_CAP	Pathogenic	0.39	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.7	H
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-5.6	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.92		Gain of disorder (P = 0.0407);
MVP		0.94
MPC		1.3
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.99
gMVP		1.0

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

LitVar

Other links and lift over

dbSNP: rs28928894; hg19: chr17-39768579;