17-41567276-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.1869C>T(p.Ser623=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000341 in 1,613,934 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 0.00012 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: KRT9 NM_000226.4 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.00600

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=-0.64).
• BP7: Synonymous conserved (PhyloP=0.006 with no splicing effect.
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.000125 (19/152044) while in subpopulation AMR AF= 0.000916 (14/15282). AF 95% confidence interval is 0.000553. There are 0 homozygotes in gnomad4. There are 12 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 19 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KRT9	NM_000226.4	c.1869C>T	p.Ser623=	synonymous_variant	7/8	ENST00000246662.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KRT9	ENST00000246662.9	c.1869C>T	p.Ser623=	synonymous_variant	7/8	1	NM_000226.4	P1
KRT9	ENST00000588431.1	c.1170C>T	p.Ser390=	synonymous_variant	8/9	1

Frequencies

GnomAD3 genomes AF: 0.000125 AC: 19 AN: 152044 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000916

Gnomad ASJ AF: 0.000289

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000321 AC: 8 AN: 249064 Hom.: 0 AF XY: 0.0000371 AC XY: 5 AN XY: 134834

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.000298

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000359

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000246 AC: 36 AN: 1461890 Hom.: 0 Cov.: 147 AF XY: 0.0000234 AC XY: 17 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000112

Gnomad4 ASJ exome AF: 0.0000765

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000153

Gnomad4 OTH exome AF: 0.000149

GnomAD4 genome AF: 0.000125 AC: 19 AN: 152044 Hom.: 0 Cov.: 31 AF XY: 0.000162 AC XY: 12 AN XY: 74252

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000916

Gnomad4 ASJ AF: 0.000289

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000588

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000494 Hom.: 0

Bravo AF: 0.000276

EpiCase AF: 0.0000545

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	-0.64
Cadd	Benign	4.8
Dann	Benign	0.70

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: rs749243428; hg19: chr17-39723528;