2-162282506-C-T

Position:

• chr2-162282506-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_022168.4(IFIH1):​c.1166G>A​(p.Gly389Glu) variant causes a missense change. The variant allele was found at a frequency of 0.0000226 in 1,459,734 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: IFIH1 NM_022168.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 3.71

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.21186876).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IFIH1	NM_022168.4	c.1166G>A	p.Gly389Glu	missense_variant	6/16	ENST00000649979.2	NP_071451.2
IFIH1	XM_047445407.1	c.449G>A	p.Gly150Glu	missense_variant	5/15		XP_047301363.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IFIH1	ENST00000649979.2	c.1166G>A	p.Gly389Glu	missense_variant	6/16		NM_022168.4	ENSP00000497271	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000401 AC: 1 AN: 249636 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 134988

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000888

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000226 AC: 33 AN: 1459734 Hom.: 0 Cov.: 30 AF XY: 0.0000234 AC XY: 17 AN XY: 726248

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: 0.0000288

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000586 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 05, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Apr 15, 2021	Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Aicardi-Goutieres syndrome 7;C4225427:Singleton-Merten syndrome 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 25, 2023	This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 389 of the IFIH1 protein (p.Gly389Glu). This variant is present in population databases (rs765985079, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with IFIH1-related conditions. ClinVar contains an entry for this variant (Variation ID: 291088). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (Invitae) indicates that this missense variant is not expected to disrupt IFIH1 function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Oct 31, 2018	- -

IFIH1-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 30, 2022

The IFIH1 c.1166G>A variant is predicted to result in the amino acid substitution p.Gly389Glu. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0016% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-163139016-C-T). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.34
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.12	T;T;.
Eigen	Uncertain	0.27
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.84	.;T;D
M_CAP	Benign	0.015	T
MetaRNN	Benign	0.21	T;T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	0.82	L;L;.
MutationTaster	Benign	0.66	D;D
PrimateAI	Benign	0.32	T
PROVEAN	Benign	-1.6	.;N;.
REVEL	Benign	0.17
Sift	Benign	0.15	.;T;.
Sift4G	Benign	0.65	.;T;.
Polyphen		0.98	D;D;.
Vest4		0.78
MVP		0.65
MPC		0.17
ClinPred		0.68	D
GERP RS		4.0
Varity_R		0.41
gMVP		0.75

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs765985079; hg19: chr2-163139016;