dbSNP rs515726146: SAMHD1:p.Phe217CysfsTer2 (chr20-36927228-A-AC) – ACMG Classification: Pathogenic (18 pts)

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_015474.4(SAMHD1):c.649_650insG(p.Phe217CysfsTer2) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,984 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

SAMHD1
NM_015474.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:2O:1

Conservation

PhyloP100: 8.85

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 18 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 20-36927228-A-AC is Pathogenic according to our data. Variant chr20-36927228-A-AC is described in ClinVar as [Pathogenic]. Clinvar id is 126413.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SAMHD1	NM_015474.4 link	c.649_650insG	p.Phe217CysfsTer2	frameshift_variant	Exon 6 of 16	ENST00000646673.2	NP_056289.2	Q9Y3Z3-1Q59H15
SAMHD1	NM_001363729.2 link	c.649_650insG	p.Phe217CysfsTer2	frameshift_variant	Exon 6 of 15		NP_001350658.1
SAMHD1	NM_001363733.2 link	c.649_650insG	p.Phe217CysfsTer2	frameshift_variant	Exon 6 of 16		NP_001350662.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SAMHD1	ENST00000646673.2 link	c.649_650insG	p.Phe217CysfsTer2	frameshift_variant	Exon 6 of 16		NM_015474.4	ENSP00000493536.2		Q9Y3Z3-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152146

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251460

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135902

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0000992

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461838

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727224

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.000115

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152146

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74330

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.000288

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Aicardi-Goutieres syndrome 5

Pathogenic:2Other:1

Oct 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Phe217Cysfs*2) in the SAMHD1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SAMHD1 are known to be pathogenic (PMID: 19525956, 22461318). This variant is present in population databases (no rsID available, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with Aicardi-Goutieres syndrome (PMID: 20653736). ClinVar contains an entry for this variant (Variation ID: 126413). For these reasons, this variant has been classified as Pathogenic. -

Jan 09, 2023

Illumina Laboratory Services, Illumina

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The SAMHD1 c.649_650insG (p.Phe217CysfsTer2) variant results in the insertion of a nucleotide at position c.649, causing a shift in the protein reading frame that is predicted to result in premature termination of the protein. Loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay is expected. The variant has been reported in a compound heterozygous state with a known pathogenic deletion in one individual with Aicardi-Goutieres syndrome (PMID: 20653736). This variant is reported in the Genome Aggregation Database in one allele at a frequency of 0.000325 in the Ashkenazi Jewish population (version 3.1.2). The c.649_650insG variant lies in the HD domain of the protein which is reported to be involved in nucleotide binding (PMID: 22461318). Based on the available evidence, the c.649_650insG (p.Phe217CysfsTer2) variant is classified as pathogenic for Aicardi-Goutieres syndrome. -

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.070

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

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