chr8-31068325-AAGGT-A

Position:

• chr8-31068325-AAGGT-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000553.6(WRN):​c.724_724+3delGGTA​(p.Glu242fs) variant causes a frameshift, splice donor, splice region, intron change. The variant allele was found at a frequency of 0.00000138 in 1,448,160 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: WRN NM_000553.6 frameshift, splice_donor, splice_region, intron
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.52

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]

WRN (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-31068325-AAGGT-A is Pathogenic according to our data. Variant chr8-31068325-AAGGT-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 528171.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
WRN	NM_000553.6	c.724_724+3delGGTA	p.Glu242fs	frameshift_variant, splice_donor_variant, splice_region_variant, intron_variant	7/35	ENST00000298139.7	NP_000544.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
WRN	ENST00000298139.7	c.724_724+3delGGTA	p.Glu242fs	frameshift_variant, splice_donor_variant, splice_region_variant, intron_variant	7/35	1	NM_000553.6	ENSP00000298139.5
WRN	ENST00000651642.1	c.19_19+3delGGTA	p.Glu7fs	frameshift_variant, splice_donor_variant, splice_region_variant, intron_variant	1/4			ENSP00000498779.1
WRN	ENST00000650667.1	n.*338_*338+3delGGTA		splice_region_variant, non_coding_transcript_exon_variant	6/34			ENSP00000498593.1
WRN	ENST00000650667.1	n.*338_*338+3delGGTA		splice_donor_variant, splice_region_variant, 3_prime_UTR_variant, intron_variant	6/34			ENSP00000498593.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1448160 Hom.: 0 AF XY: 0.00000139 AC XY: 1 AN XY: 720714

Gnomad4 AFR exome AF: 0.00

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: 0.00000182

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Werner syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 23, 2017

Nucleotide substitutions within the consensus splice site are relatively common causes of aberrant splicing (PMID: 17576681, 9536098), and loss-of-function variants in WRN are known to be pathogenic (PMID: 16673358). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site and result in an absent or disrupted protein product, but this prediction has not been confirmed by published transcriptional studies. This sequence change removes the last nucleotide of exon 7 and the first 3 nucleotides of intron 7 of the WRN gene. It does not directly change the donor splice site in intron 7 of the WRN gene, but it does affect several nucleotides within the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. 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). -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.91		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.91		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554519449; hg19: chr8-30925841;