NM_015474.4:c.1877T>A

Variant names:

• chr20-36892936-A-T
• rs1269278007
• NM_015474.4:c.1877T>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_015474.4(SAMHD1):​c.1877T>A​(p.Met626Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M626V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SAMHD1 NM_015474.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.249
• Publications: 0 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]

TLDC2 (HGNC:16112): (TBC/LysM-associated domain containing 2) Predicted to be involved in response to oxidative stress. Predicted to act upstream of or within negative regulation of oxidative stress-induced neuron death. Predicted to be active in nucleus. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.075193614).

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.1877T>A	p.Met626Lys	missense	Exon 16 of 16	NP_056289.2
	TLDC2	NM_080628.3	MANE Select	c.*92A>T		3_prime_UTR	Exon 7 of 7	NP_542195.1	A0PJX2
	SAMHD1	NM_001363729.2		c.1772T>A	p.Met591Lys	missense	Exon 15 of 15	NP_001350658.1	Q9Y3Z3-4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SAMHD1	ENST00000646673.2	MANE Select	c.1877T>A	p.Met626Lys	missense	Exon 16 of 16	ENSP00000493536.2	Q9Y3Z3-1
	SAMHD1	ENST00000262878.5	TSL:1	c.1772T>A	p.Met591Lys	missense	Exon 15 of 15	ENSP00000262878.5	Q9Y3Z3-4
	TLDC2	ENST00000217320.8	TSL:1 MANE Select	c.*92A>T		3_prime_UTR	Exon 7 of 7	ENSP00000217320.3	A0PJX2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000401 AC: 1 AN: 249230 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000137 AC: 2 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

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

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Aicardi-Goutieres syndrome 5 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.088
BayesDel_addAF	Benign	-0.069	T
BayesDel_noAF	Benign	-0.25
CADD	Benign	2.6
DANN	Benign	0.58
DEOGEN2	Benign	0.064	T
Eigen	Benign	-2.0
Eigen_PC	Benign	-2.0
FATHMM_MKL	Benign	0.033	N
LIST_S2	Benign	0.44	T
M_CAP	Uncertain	0.12	D
MetaRNN	Benign	0.075	T
MetaSVM	Benign	-0.29	T
MutationAssessor	Benign	0.0	N
PhyloP100		-0.25
PrimateAI	Benign	0.29	T
REVEL	Benign	0.21
Polyphen		0.0	B
MutPred		0.40		Gain of MoRF binding (P = 0.0075)
MVP		0.11
MPC		0.81
ClinPred		0.042	T
GERP RS		-3.7
Varity_R		0.17
gMVP		0.31
Mutation Taster		=99/1	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1269278007; hg19: chr20-35521339;