chr20-36904251-T-C

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_ModeratePM2PP5_Very_Strong

The NM_015474.4(SAMHD1):c.1411-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000187 in 1,601,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

SAMHD1
NM_015474.4 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5O:1

Conservation

PhyloP100: 5.70

Variant links:

Genes affected

SAMHD1 (HGNC:15925): (SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1) This gene may play a role in regulation of the innate immune response. The encoded protein is upregulated in response to viral infection and may be involved in mediation of tumor necrosis factor-alpha proinflammatory responses. Mutations in this gene have been associated with Aicardi-Goutieres syndrome. [provided by RefSeq, Mar 2010]

SAMHD1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.049441785 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 20-36904251-T-C is Pathogenic according to our data. Variant chr20-36904251-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 126407.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr20-36904251-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	Exon rank	MANE	Protein	UniProt
SAMHD1	NM_015474.4 link	c.1411-2A>G	splice_acceptor_variant, intron_variant	Intron 12 of 15	ENST00000646673.2	NP_056289.2	Q9Y3Z3-1Q59H15
SAMHD1	NM_001363729.2 link	c.1411-2A>G	splice_acceptor_variant, intron_variant	Intron 12 of 14		NP_001350658.1
SAMHD1	NM_001363733.2 link	c.1411-2A>G	splice_acceptor_variant, intron_variant	Intron 12 of 15		NP_001350662.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SAMHD1	ENST00000646673.2 link	c.1411-2A>G		splice_acceptor_variant, intron_variant	Intron 12 of 15		NM_015474.4	ENSP00000493536.2		Q9Y3Z3-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.90e-7

AC:

AN:

1448902

Hom.:

Cov.:

AF XY:

0.00000139

AC XY:

AN XY:

721810

show subpopulations

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:

9.09e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152158

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74336

show subpopulations

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:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000383

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

May 16, 2022

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 27, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Canonical splice site variant predicted to result in an in-frame loss of the adjacent exon in a gene for which loss of function is a known mechanism of disease; Published functional studies demonstrate skipping of exon 13 and degradation of the SAMHD1 protein in cell lysates from an affected individual (PMID: 21402907); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 21633013, 31028937, 19525956, 28289923, 22461318, 34852373, 20301648, 21402907, 27943079) -

Aicardi-Goutieres syndrome 5

Pathogenic:1Other:1

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Jan 06, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 12 of the SAMHD1 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs515726141, gnomAD 0.0009%). Disruption of this splice site has been observed in individual(s) with cerebral vasculopathy and early onset of stroke (PMID: 21402907). ClinVar contains an entry for this variant (Variation ID: 126407). Studies have shown that disruption of this splice site results in skipping of exon 13, but is expected to preserve the integrity of the reading-frame (PMID: 21402907). For these reasons, this variant has been classified as Pathogenic. -

Aicardi-Goutieres syndrome 5;C3280721:Chilblain lupus 2

Pathogenic:1

Apr 09, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

SAMHD1-related disorder

Pathogenic:1

Apr 23, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The SAMHD1 c.1411-2A>G variant is predicted to disrupt the AG splice acceptor site and interfere with normal splicing. This variant has been reported in the homozygous state to be causative for autosomal recessive Aicardi-Goutiѐres syndrome (Xin et al. 2011. PubMed ID: 21402907, Crow. 2016. PubMed ID: 20301648). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Variants that disrupt the consensus splice acceptor site in SAMHD1 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Uncertain

-0.030

CADD

Pathogenic

DANN

Uncertain

0.98

Eigen

Pathogenic

0.86

Eigen_PC

Uncertain

0.64

FATHMM_MKL

Pathogenic

0.98

GERP RS

5.3

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.84

SpliceAI score (max)

1.0

Details are displayed if max score is > 0.2

DS_AL_spliceai

1.0

Position offset: -2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over