8-31147123-A-G

Position:

• chr8-31147123-A-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000553.6(WRN):​c.3454A>G​(p.Thr1152Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: WRN NM_000553.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.152

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.06478521).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
WRN	NM_000553.6	c.3454A>G	p.Thr1152Ala	missense_variant	29/35	ENST00000298139.7	NP_000544.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
WRN	ENST00000298139.7	c.3454A>G	p.Thr1152Ala	missense_variant	29/35	1	NM_000553.6	ENSP00000298139	P1
WRN	ENST00000521620.5	n.2087A>G		non_coding_transcript_exon_variant	17/23	1
WRN	ENST00000650667.1	c.*3068A>G		3_prime_UTR_variant, NMD_transcript_variant	28/34			ENSP00000498593

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

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

Aug 05, 2017

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 alanine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. In addition, an experimental study has shown that the Thr1152Ala missense change, in combination with additional WRN missense changes, results in reduced ATR phosphorylation at residues important for correct WRN nuclear localization and replication protein A (RPA) co-localization (PMID: 20802463). However, the clinical significance of this finding is unclear, as the impact of each individual missense change was not specifically assessed. 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. 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 threonine with alanine at codon 1152 of the WRN protein (p.Thr1152Ala). The threonine residue is moderately conserved and there is a small physicochemical difference between threonine and alanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.71
CADD	Benign	17
DANN	Benign	0.60
DEOGEN2	Benign	0.12	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.034	N
LIST_S2	Benign	0.51	T
M_CAP	Benign	0.0035	T
MetaRNN	Benign	0.065	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.89	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-0.92	N
REVEL	Benign	0.056
Sift	Benign	0.56	T
Sift4G	Benign	0.74	T
Polyphen		0.0	B
Vest4		0.055
MutPred		0.25		Gain of loop (P = 0.1069);
MVP		0.26
MPC		0.064
ClinPred		0.014	T
GERP RS		-4.8
Varity_R		0.041
gMVP		0.26

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1309001891; hg19: chr8-31004639;