Genetic Variant IFIH1:c.2454+6T>C (chr2-162273789-A-G) – ACMG Classification: Benign (-20 pts)

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBA1

The NM_022168.4(IFIH1):c.2454+6T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00365 in 1,540,164 control chromosomes in the GnomAD database, including 201 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.020 ( 109 hom., cov: 32)

Exomes 𝑓: 0.0019 ( 92 hom. )

Consequence

IFIH1
NM_022168.4 splice_region, intron

Scores

Splicing: ADA: 0.01695

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: 0.476

Variant links:

Genes affected

IFIH1 (HGNC:18873): (interferon induced with helicase C domain 1) IFIH1 encodes MDA5 which is an intracellular sensor of viral RNA that triggers the innate immune response. Sensing RNA length and secondary structure, MDA5 binds dsRNA oligonucleotides with a modified DExD/H-box helicase core and a C-terminal domain, thus leading to a proinflammatory response that includes interferons. It has been shown that Coronaviruses (CoVs) as well as various other virus families, are capable of evading the MDA5-dependent interferon response, thus impeding the activation of the innate immune response to infection. MDA5 has also been shown to play an important role in enhancing natural killer cell function in malaria infection. In addition to its protective role in antiviral responses, MDA5 has been implicated in autoimmune and autoinflammatory diseases such as type 1 diabetes, systemic lupus erythematosus, and Aicardi-Goutieres syndrome[provided by RefSeq, Jul 2020]

IFIH1 links:

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.68).

BP6

Variant 2-162273789-A-G is Benign according to our data. Variant chr2-162273789-A-G is described in ClinVar as [Benign]. Clinvar id is 474948.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BA1

GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0687 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IFIH1	NM_022168.4 link	c.2454+6T>C		splice_region_variant, intron_variant	Intron 12 of 15	ENST00000649979.2	NP_071451.2	Q9BYX4-1
IFIH1	XM_047445407.1 link	c.1737+6T>C		splice_region_variant, intron_variant	Intron 11 of 14		XP_047301363.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IFIH1	ENST00000649979.2 link	c.2454+6T>C		splice_region_variant, intron_variant	Intron 12 of 15		NM_022168.4	ENSP00000497271.1		Q9BYX4-1

Frequencies

GnomAD3 genomes

AF:

0.0201

AC:

3054

AN:

152194

Hom.:

109

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0710

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00517

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000413

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000162

Gnomad OTH

AF:

0.0100

GnomAD3 exomes

AF:

0.00561

AC:

1135

AN:

202294

Hom.:

AF XY:

0.00397

AC XY:

438

AN XY:

110362

show subpopulations

Gnomad AFR exome

AF:

0.0742

Gnomad AMR exome

AF:

0.00313

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000183

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000102

Gnomad OTH exome

AF:

0.00307

GnomAD4 exome

AF:

0.00185

AC:

2571

AN:

1387852

Hom.:

Cov.:

AF XY:

0.00159

AC XY:

1095

AN XY:

688628

show subpopulations

Gnomad4 AFR exome

AF:

0.0735

Gnomad4 AMR exome

AF:

0.00372

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000107

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000418

Gnomad4 OTH exome

AF:

0.00376

GnomAD4 genome

AF:

0.0201

AC:

3057

AN:

152312

Hom.:

109

Cov.:

AF XY:

0.0188

AC XY:

1402

AN XY:

74480

show subpopulations

Gnomad4 AFR

AF:

0.0708

Gnomad4 AMR

AF:

0.00517

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000162

Gnomad4 OTH

AF:

0.00992

Alfa

AF:

0.0110

Hom.:

Bravo

AF:

0.0231

Asia WGS

AF:

0.00202

AC:

AN:

3478

ClinVar

Significance: Benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:2

Jun 30, 2021

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Breakthrough Genomics, Breakthrough Genomics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

Aicardi-Goutieres syndrome 7;C4225427:Singleton-Merten syndrome 1

Benign:1

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.68

CADD

Benign

8.4

DANN

Benign

0.60

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.017

dbscSNV1_RF

Benign

0.27

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over