rs121434516

Variant names:

• chr20-36930760-C-T
• rs121434516
• NM_015474.4:c.625G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PP3_Strong PP5_Moderate

The NM_015474.4(SAMHD1):​c.625G>A​(p.Gly209Ser) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000005 in 1,601,102 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 15/26 in silico tools predict a damaging outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G209C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: SAMHD1 NM_015474.4 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2 O:1
• Conservation: PhyloP100: 7.81
• Publications: 8 publications found

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 Gene-Disease associations (from GenCC):

• Aicardi-Goutieres syndrome 5

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, Genomics England PanelApp
• SAMHD1-related type 1 interferonopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Moyamoya disease

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
• Aicardi-Goutieres syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial chilblain lupus

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• chilblain lupus 2

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• chilblain lupus

  Inheritance: AD Classification: NO_KNOWN Submitted by: Illumina

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
• PP5: Variant 20-36930760-C-T is Pathogenic according to our data. Variant chr20-36930760-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 4066.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015474.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SAMHD1	NM_015474.4	MANE Select	c.625G>A	p.Gly209Ser	missense splice_region	Exon 5 of 16	NP_056289.2
	SAMHD1	NM_001363729.2		c.625G>A	p.Gly209Ser	missense splice_region	Exon 5 of 15	NP_001350658.1	Q9Y3Z3-4
	SAMHD1	NM_001363733.2		c.625G>A	p.Gly209Ser	missense splice_region	Exon 5 of 16	NP_001350662.1	A0A2R8YCS7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SAMHD1	ENST00000646673.2	MANE Select	c.625G>A	p.Gly209Ser	missense splice_region	Exon 5 of 16	ENSP00000493536.2	Q9Y3Z3-1
	SAMHD1	ENST00000262878.5	TSL:1	c.625G>A	p.Gly209Ser	missense splice_region	Exon 5 of 15	ENSP00000262878.5	Q9Y3Z3-4
	SAMHD1	ENST00000866371.1		c.625G>A	p.Gly209Ser	missense splice_region	Exon 5 of 17	ENSP00000536430.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151964 Hom.: 0 Cov.: 32

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

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251276 AF XY: 0.00000736

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000483 AC: 7 AN: 1449138 Hom.: 0 Cov.: 28 AF XY: 0.00000416 AC XY: 3 AN XY: 721726

African (AFR) AF: 0.00 AC: 0 AN: 33178

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26064

East Asian (EAS) AF: 0.00 AC: 0 AN: 39624

South Asian (SAS) AF: 0.00 AC: 0 AN: 85966

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53260

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00000545 AC: 6 AN: 1100622

Other (OTH) AF: 0.0000167 AC: 1 AN: 59950

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151964 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74192

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000242 AC: 1 AN: 41374

American (AMR) AF: 0.00 AC: 0 AN: 15250

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5186

South Asian (SAS) AF: 0.00 AC: 0 AN: 4802

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10580

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67986

Other (OTH) AF: 0.00 AC: 0 AN: 2088

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.0000148 Hom.: 0

Bravo AF: 0.0000189

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
2	-	-	Aicardi-Goutieres syndrome 5 (3)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.61
CADD	Pathogenic	34
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.72	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.1	H
PhyloP100		7.8
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-5.9	D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.96		Gain of disorder (P = 0.0994)
MVP		0.99
MPC		1.4
ClinPred		1.0	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.95
gMVP		0.88
Mutation Taster		=6/94	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.45		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.45		Position offset: 0

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

Other links and lift over

dbSNP: rs121434516; hg19: chr20-35559163;