chr2-162267272-C-A

Position:

• chr2-162267272-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_022168.4(IFIH1):​c.3006G>T​(p.Lys1002Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,459,714 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: IFIH1 NM_022168.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.540

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.41764855).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IFIH1	NM_022168.4	c.3006G>T	p.Lys1002Asn	missense_variant	16/16	ENST00000649979.2	NP_071451.2
IFIH1	XM_047445407.1	c.2289G>T	p.Lys763Asn	missense_variant	15/15		XP_047301363.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IFIH1	ENST00000649979.2	c.3006G>T	p.Lys1002Asn	missense_variant	16/16		NM_022168.4	ENSP00000497271	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1459714 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 725938

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 20, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with IFIH1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 1002 of the IFIH1 protein (p.Lys1002Asn). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
BayesDel_addAF	Benign	-0.079	T
BayesDel_noAF	Benign	-0.35
CADD	Benign	17
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.49	T;T;.
Eigen	Uncertain	0.21
Eigen_PC	Benign	0.086
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.88	.;D;D
M_CAP	Benign	0.049	D
MetaRNN	Benign	0.42	T;T;T
MetaSVM	Benign	-0.57	T
MutationAssessor	Pathogenic	3.2	M;M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.55	T
PROVEAN	Uncertain	-3.1	.;D;.
REVEL	Benign	0.28
Sift	Uncertain	0.0020	.;D;.
Sift4G	Uncertain	0.0040	.;D;.
Polyphen		0.95	P;P;.
Vest4		0.44
MutPred		0.47		Loss of methylation at K1002 (P = 0.0028);Loss of methylation at K1002 (P = 0.0028);.;
MVP		0.77
MPC		0.19
ClinPred		0.99	D
GERP RS		0.48
Varity_R		0.91
gMVP		0.84

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-163123782;