17-41567306-G-A

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 0P and 10B. BP4_Strong BP7 BS1_Supporting BS2

The NM_000226.4(KRT9):c.1839C>T(p.Tyr613=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000446 in 1,613,950 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000045 (0 hom.)
• Consequence: KRT9 NM_000226.4 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.96

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 Benign. Variant got -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.92).
• BP7: Synonymous conserved (PhyloP=-1.96 with no splicing effect.
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.0000395 (6/152090) while in subpopulation EAS AF= 0.000386 (2/5184). AF 95% confidence interval is 0.0000683. There are 0 homozygotes in gnomad4. There are 2 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAd at 6 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KRT9	NM_000226.4	c.1839C>T	p.Tyr613=	synonymous_variant	7/8	ENST00000246662.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KRT9	ENST00000246662.9	c.1839C>T	p.Tyr613=	synonymous_variant	7/8	1	NM_000226.4	P1
KRT9	ENST00000588431.1	c.1140C>T	p.Tyr380=	synonymous_variant	8/9	1

Frequencies

GnomAD3 genomes AF: 0.0000395 AC: 6 AN: 151972 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000484

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000385

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000362 AC: 9 AN: 248802 Hom.: 0 AF XY: 0.0000520 AC XY: 7 AN XY: 134722

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000218

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000899

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000451 AC: 66 AN: 1461860 Hom.: 0 Cov.: 147 AF XY: 0.0000509 AC XY: 37 AN XY: 727226

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00131

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000395 AC: 6 AN: 152090 Hom.: 0 Cov.: 31 AF XY: 0.0000269 AC XY: 2 AN XY: 74360

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000386

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000555 Hom.: 0

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Palmoplantar keratoderma, epidermolytic Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.92
Cadd	Benign	0.98
Dann	Benign	0.73

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: rs142173628; hg19: chr17-39723558;