8-31150346-C-A

Position:

• chr8-31150346-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000553.6(WRN):​c.3578C>A​(p.Thr1193Asn) 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 pathogenic 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: 3.37

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.781

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
WRN	NM_000553.6	c.3578C>A	p.Thr1193Asn	missense_variant	31/35	ENST00000298139.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
WRN	ENST00000298139.7	c.3578C>A	p.Thr1193Asn	missense_variant	31/35	1	NM_000553.6	P1
WRN	ENST00000521620.5	n.2211C>A		non_coding_transcript_exon_variant	19/23	1
WRN	ENST00000650667.1	c.*3192C>A		3_prime_UTR_variant, NMD_transcript_variant	30/34

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000712 Hom.: 0

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

Sep 12, 2017

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 do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C55"). 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 asparagine at codon 1193 of the WRN protein (p.Thr1193Asn). The threonine residue is highly conserved and there is a small physicochemical difference between threonine and asparagine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.33	T
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.90	D
M_CAP	Benign	0.016	T
MetaRNN	Pathogenic	0.78	D
MetaSVM	Uncertain	-0.15	T
MutationAssessor	Uncertain	2.7	M
MutationTaster	Benign	0.72	D
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	-2.2	N
REVEL	Benign	0.17
Sift	Benign	0.059	T
Sift4G	Benign	0.11	T
Polyphen		0.97	D
Vest4		0.58
MutPred		0.37		Loss of glycosylation at T1193 (P = 0.0338);
MVP		0.78
MPC		0.42
ClinPred		0.95	D
GERP RS		4.1
Varity_R		0.37
gMVP		0.52

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs1267766243; hg19: chr8-31007862;