chr20-36892887-G-A

Position:

• chr20-36892887-G-A

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BS1 BS2

The NM_015474.4(SAMHD1):​c.*45C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000849 in 1,611,640 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.0038 (3 hom., cov: 32)
  • Exomes 𝑓: 0.00054 (4 hom.)
• Consequence: SAMHD1 NM_015474.4 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:2
• Conservation: PhyloP100: -0.232

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

Verdict is Benign. Variant got -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP6: Variant 20-36892887-G-A is Benign according to our data. Variant chr20-36892887-G-A is described in ClinVar as [Benign]. Clinvar id is 338339.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0038 (578/152164) while in subpopulation AFR AF= 0.0123 (510/41508). AF 95% confidence interval is 0.0114. There are 3 homozygotes in gnomad4. There are 282 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 3 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SAMHD1	NM_015474.4	c.*45C>T		3_prime_UTR_variant	16/16	ENST00000646673.2
TLDC2	NM_080628.3	c.*43G>A		3_prime_UTR_variant	7/7	ENST00000217320.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TLDC2	ENST00000217320.8	c.*43G>A		3_prime_UTR_variant	7/7	1	NM_080628.3	P1
SAMHD1	ENST00000646673.2	c.*45C>T		3_prime_UTR_variant	16/16		NM_015474.4	P1

Frequencies

GnomAD3 genomes AF: 0.00374 AC: 569 AN: 152046 Hom.: 2 Cov.: 32

Gnomad AFR AF: 0.0121

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00334

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.0127

Gnomad NFE AF: 0.0000882

Gnomad OTH AF: 0.00335

GnomAD3 exomes AF: 0.00112 AC: 278 AN: 249052 Hom.: 1 AF XY: 0.000942 AC XY: 127 AN XY: 134814

Gnomad AFR exome AF: 0.0114

Gnomad AMR exome AF: 0.00162

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: 0.000242

Gnomad OTH exome AF: 0.00147

GnomAD4 exome AF: 0.000541 AC: 790 AN: 1459476 Hom.: 4 Cov.: 29 AF XY: 0.000503 AC XY: 365 AN XY: 726264

Gnomad4 AFR exome AF: 0.0130

Gnomad4 AMR exome AF: 0.00172

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000163

Gnomad4 OTH exome AF: 0.00134

GnomAD4 genome AF: 0.00380 AC: 578 AN: 152164 Hom.: 3 Cov.: 32 AF XY: 0.00379 AC XY: 282 AN XY: 74364

Gnomad4 AFR AF: 0.0123

Gnomad4 AMR AF: 0.00334

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00331

Alfa AF: 0.00142 Hom.: 1

Bravo AF: 0.00413

Asia WGS AF: 0.00231 AC: 8 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:2

Revision: criteria provided, single submitter

Submissions by phenotype

Chilblain lupus 2 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Aicardi-Goutieres syndrome 5 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
CADD	Benign	0.80
DANN	Benign	0.25

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.18		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

Other links and lift over

dbSNP: rs115645414; hg19: chr20-35521290;