12-52487812-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_005554.4(KRT6A):c.1603A>T(p.Ile535Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,730 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I535T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KRT6A NM_005554.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -3.77

Genes affected

KRT6A (HGNC:6443): (keratin 6A) 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. As many as six of this type II cytokeratin (KRT6) have been identified; the multiplicity of the genes is attributed to successive gene duplication events. The genes are expressed with family members KRT16 and/or KRT17 in the filiform papillae of the tongue, the stratified epithelial lining of oral mucosa and esophagus, the outer root sheath of hair follicles, and the glandular epithelia. This KRT6 gene in particular encodes the most abundant isoform. Mutations in these genes have been associated with pachyonychia congenita. In addition, peptides from the C-terminal region of the protein have antimicrobial activity against bacterial pathogens. The type II cytokeratins are clustered in a region of chromosome 12q12-q13. [provided by RefSeq, Oct 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.099265754).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KRT6A	NM_005554.4	c.1603A>T	p.Ile535Phe	missense_variant	9/9	ENST00000330722.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KRT6A	ENST00000330722.7	c.1603A>T	p.Ile535Phe	missense_variant	9/9	1	NM_005554.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461730 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 727172

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 10, 2023

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Not Available"; Align-GVGD: "Not Available". The phenylalanine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with KRT6A-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces isoleucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 535 of the KRT6A protein (p.Ile535Phe). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.064
BayesDel_addAF	Benign	-0.093	T
BayesDel_noAF	Benign	-0.37
Cadd	Benign	0.023
Dann	Benign	0.65
DEOGEN2	Benign	0.12	T
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.026	N
LIST_S2	Benign	0.12	T
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.099	T
MetaSVM	Benign	-0.64	T
MutationAssessor	Uncertain	2.1	M
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-1.0	N
REVEL	Benign	0.27
Sift	Benign	0.061	T
Sift4G	Benign	0.72	T
Polyphen		0.019	B
Vest4		0.069
MutPred		0.40		Gain of catalytic residue at S531 (P = 0.0081);
MVP		0.67
MPC		0.44
ClinPred		0.22	T
GERP RS		-10
Varity_R		0.061
gMVP		0.26

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: chr12-52881596;