3-48466313-A-G

Position:

• chr3-48466313-A-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_033629.6(TREX1):​c.-27+4A>G variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00000324 in 618,018 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000032 (0 hom.)
• Consequence: TREX1 NM_033629.6 splice_region, intron
• Scores: Splicing: ADA: 0.002207
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.91

Genes affected

ATRIP (HGNC:33499): (ATR interacting protein) This gene encodes an essential component of the DNA damage checkpoint. The encoded protein binds to single-stranded DNA coated with replication protein A. The protein also interacts with the ataxia telangiectasia and Rad3 related protein kinase, resulting in its accumulation at intranuclear foci induced by DNA damage. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2012]

TREX1 (HGNC:12269): (three prime repair exonuclease 1) This gene encodes a nuclear protein with 3' exonuclease activity. The encoded protein may play a role in DNA repair and serve as a proofreading function for DNA polymerase. Mutations in this gene result in Aicardi-Goutieres syndrome, chilblain lupus, Cree encephalitis, and other diseases of the immune system. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2012]

ATRIP-TREX1 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.59).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ATRIP	NM_130384.3	c.*759A>G		3_prime_UTR_variant	13/13	ENST00000320211.10	NP_569055.1
TREX1	NM_033629.6	c.-27+4A>G		splice_region_variant, intron_variant		ENST00000625293.3	NP_338599.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ATRIP	ENST00000320211.10	c.*759A>G		3_prime_UTR_variant	13/13	1	NM_130384.3	ENSP00000323099.3
TREX1	ENST00000625293.3	c.-27+4A>G		splice_region_variant, intron_variant		6	NM_033629.6	ENSP00000486676.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000324 AC: 2 AN: 618018 Hom.: 0 Cov.: 8 AF XY: 0.00000619 AC XY: 2 AN XY: 323310

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000520

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Aicardi-Goutieres syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Jul 17, 2023

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3A. Following criteria are met: 0103 - Dominant negative and loss of function are known mechanisms of disease in this gene and are associated with TREX1-related conditions. Loss of function is generally associated with recessive disease while dominant negative variants are associated with dominant disease (OMIM, PMID: 21937424). However, loss of function is the mechanism of disease associated with heterozygous C-terminal frameshift variants identified in individuals with Retinal Vasculopathy with Cerebral Leukodystrophy (OMIM). (I) 0108 - This gene is known to be associated with both recessive and dominant disease. Aicardi-Goutieres syndrome is predominantly a recessive condition; however, there have been rare cases of a dominant form of the disease reported (OMIM). (I) 0218 - Non-coding variant without known or predicted effect. (I) 0252 - This variant is homozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0508 - In silico predictions for abnormal splicing are conflicting. (I) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0705 - No comparable non-coding variants have previous evidence for pathogenicity. (I) 0807 - This variant has no previous evidence of pathogenicity in the literature. However, this variant was found to be biallelic in a research setting, in another individual with a typical Aicardi-Goutières syndrome phenotype (Professor Yanick Crow, personal communication). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1101 - Very strong and specific phenotype match for this individual. (SP) 1209 - This variant has been shown to be both maternally and paternally inherited (biallelic) (by Sanger sequencing segregation analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.59
CADD	Benign	18
DANN	Benign	0.67

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0022
dbscSNV1_RF	Benign	0.020
SpliceAI score (max)		0.40		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.40		Position offset: -4

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

Publications

LitVar

Other links and lift over

dbSNP: rs2040293250; hg19: chr3-48507712;