chr20-36927182-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_015474.4(SAMHD1):​c.696G>A​(p.Thr232=) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.00000498 in 1,607,398 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

SAMHD1
NM_015474.4 splice_region, synonymous

Scores

2
Splicing: ADA: 0.9999
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.43
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
SAMHD1NM_015474.4 linkuse as main transcriptc.696G>A p.Thr232= splice_region_variant, synonymous_variant 6/16 ENST00000646673.2 NP_056289.2
SAMHD1NM_001363729.2 linkuse as main transcriptc.696G>A p.Thr232= splice_region_variant, synonymous_variant 6/15 NP_001350658.1
SAMHD1NM_001363733.2 linkuse as main transcriptc.696G>A p.Thr232= splice_region_variant, synonymous_variant 6/16 NP_001350662.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
SAMHD1ENST00000646673.2 linkuse as main transcriptc.696G>A p.Thr232= splice_region_variant, synonymous_variant 6/16 NM_015474.4 ENSP00000493536 P1Q9Y3Z3-1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151946
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000795
AC:
2
AN:
251468
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135908
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000481
AC:
7
AN:
1455452
Hom.:
0
Cov.:
30
AF XY:
0.00000414
AC XY:
3
AN XY:
724402
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:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000271
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151946
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74180
show subpopulations
Gnomad4 AFR
AF:
0.0000242
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:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000508
Hom.:
0
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Aicardi-Goutieres syndrome 5 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpMay 01, 2021This sequence change affects codon 232 of the SAMHD1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the SAMHD1 protein. This variant also falls at the last nucleotide of exon 6, which is part of the consensus splice site for this exon. This variant is present in population databases (rs763408711, ExAC 0.001%). This variant has not been reported in the literature in individuals with SAMHD1-related conditions. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.13
CADD
Benign
20
DANN
Benign
0.95

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.99
SpliceAI score (max)
0.60
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.60
Position offset: 0

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.

Other links and lift over

dbSNP: rs763408711; hg19: chr20-35555585; COSMIC: COSV53431142; COSMIC: COSV53431142; API