chr8-31076203-A-G

Position:

• chr8-31076203-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000553.6(WRN):​c.755A>G​(p.Lys252Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,152 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 (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: WRN NM_000553.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.42

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.

• PM1: In a cross_link Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in SUMO2) (size 0) in uniprot entity WRN_HUMAN
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.20229277).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
WRN	NM_000553.6	c.755A>G	p.Lys252Arg	missense_variant	8/35	ENST00000298139.7	NP_000544.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
WRN	ENST00000298139.7	c.755A>G	p.Lys252Arg	missense_variant	8/35	1	NM_000553.6	ENSP00000298139	P1
WRN	ENST00000651642.1	c.50A>G	p.Lys17Arg	missense_variant	2/4			ENSP00000498779
WRN	ENST00000650667.1	c.*369A>G		3_prime_UTR_variant, NMD_transcript_variant	7/34			ENSP00000498593

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152152 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

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

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152152 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74326

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

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

Dec 19, 2016

This sequence change replaces lysine with arginine at codon 252 of the WRN protein (p.Lys252Arg). The lysine residue is moderately conserved and there is a small physicochemical difference between lysine and arginine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a WRN-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: (SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). The arginine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies. In summary, this variant is a rare missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.59
CADD	Benign	19
DANN	Uncertain	0.99
DEOGEN2	Benign	0.12	T
Eigen	Benign	0.030
Eigen_PC	Benign	0.10
FATHMM_MKL	Uncertain	0.83	D
LIST_S2	Benign	0.78	T
M_CAP	Benign	0.0095	T
MetaRNN	Benign	0.20	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.7	M
MutationTaster	Benign	0.99	N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-1.4	N
REVEL	Benign	0.17
Sift	Benign	0.22	T
Sift4G	Benign	0.30	T
Polyphen		0.64	P
Vest4		0.073
MutPred		0.53		Loss of ubiquitination at K252 (P = 0.0087);
MVP		0.67
MPC		0.065
ClinPred		0.74	D
GERP RS		4.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.053
gMVP		0.24

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: rs1060500077; hg19: chr8-30933719;