8-31064419-G-T

Position:

• chr8-31064419-G-T

Variant summary

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

The NM_000553.6(WRN):​c.340G>T​(p.Val114Phe) 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 1,461,764 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. V114I) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: WRN NM_000553.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0360

Genes affected

WRN (HGNC:12791): (WRN RecQ like helicase) This gene encodes a member of the RecQ subfamily of DNA helicase proteins. The encoded nuclear protein is important in the maintenance of genome stability and plays a role in DNA repair, replication, transcription and telomere maintenance. This protein contains a N-terminal 3' to 5' exonuclease domain, an ATP-dependent helicase domain and RQC (RecQ helicase conserved region) domain in its central region, and a C-terminal HRDC (helicase RNase D C-terminal) domain and nuclear localization signal. Defects in this gene are the cause of Werner syndrome, an autosomal recessive disorder characterized by accelerated aging and an elevated risk for certain cancers. [provided by RefSeq, Aug 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
WRN	NM_000553.6	c.340G>T	p.Val114Phe	missense_variant	4/35	ENST00000298139.7	NP_000544.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
WRN	ENST00000298139.7	c.340G>T	p.Val114Phe	missense_variant	4/35	1	NM_000553.6	ENSP00000298139.5
WRN	ENST00000650667.1	n.210-496G>T		intron_variant				ENSP00000498593.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461764 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727184

Gnomad4 AFR exome AF: 0.0000299

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Werner syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 16, 2018

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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with WRN-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces valine with phenylalanine at codon 114 of the WRN protein (p.Val114Phe). The valine residue is weakly conserved and there is a small physicochemical difference between valine and phenylalanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.43
BayesDel_addAF	Benign	-0.079	T
BayesDel_noAF	Benign	-0.35
CADD	Benign	18
DANN	Uncertain	1.0
DEOGEN2	Benign	0.24	T
Eigen	Benign	-0.30
Eigen_PC	Benign	-0.38
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.62	T
M_CAP	Uncertain	0.11	D
MetaRNN	Uncertain	0.57	D
MetaSVM	Benign	-0.36	T
MutationAssessor	Uncertain	2.5	M
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-1.9	N
REVEL	Benign	0.26
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0030	D
Polyphen		0.99	D
Vest4		0.38
MutPred		0.77		Loss of helix (P = 0.3949);
MVP		0.68
MPC		0.37
ClinPred		0.94	D
GERP RS		2.0
Varity_R		0.54
gMVP		0.85

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.23		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.23		Position offset: 15

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

Publications

LitVar

Other links and lift over

dbSNP: rs2230009; hg19: chr8-30921935; COSMIC: COSV53295681;