2-162267272-C-A

Variant names:

• chr2-162267272-C-A
• rs776754156
• NM_022168.4:c.3006G>T

Variant summary

Our verdict is Uncertain significance. The variant received 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K1002T) has been classified 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
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• Aicardi-Goutieres syndrome 7

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Illumina
• IFIH1-related type 1 interferonopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• Singleton-Merten syndrome 1

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• Aicardi-Goutieres syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Singleton-Merten dysplasia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• immunodeficiency 95

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_022168.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IFIH1	NM_022168.4	MANE Select	c.3006G>T	p.Lys1002Asn	missense	Exon 16 of 16	NP_071451.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IFIH1	ENST00000649979.2	MANE Select	c.3006G>T	p.Lys1002Asn	missense	Exon 16 of 16	ENSP00000497271.1	Q9BYX4-1
	IFIH1	ENST00000648433.1		c.2889G>T	p.Lys963Asn	missense	Exon 15 of 15	ENSP00000496816.1	A0A3B3IRK8
	IFIH1	ENST00000679938.1		c.2694G>T	p.Lys898Asn	missense	Exon 15 of 15	ENSP00000505518.1	A0A7P0Z4A9

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

African (AFR) AF: 0.00 AC: 0 AN: 33376

American (AMR) AF: 0.00 AC: 0 AN: 44404

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39676

South Asian (SAS) AF: 0.00 AC: 0 AN: 85288

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5722

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111396

Other (OTH) AF: 0.00 AC: 0 AN: 60334

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Aicardi-Goutieres syndrome 7;C4225427:Singleton-Merten syndrome 1 (1)

Computational scores

Source: dbNSFP v4.9

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
Eigen	Uncertain	0.21
Eigen_PC	Benign	0.086
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.88	D
M_CAP	Benign	0.049	D
MetaRNN	Benign	0.42	T
MetaSVM	Benign	-0.57	T
MutationAssessor	Pathogenic	3.2	M
PhyloP100		0.54
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
Vest4		0.44
MutPred		0.47		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
Mutation Taster		=47/53	disease causing

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

Other links and lift over

dbSNP: rs776754156; hg19: chr2-163123782;