IFNAR1

Chr 21AR

interferon alpha and beta receptor subunit 1

Also known as: AVP, CRF2-1, IFN-R-1, IFN-alpha-REC, IFNAR, IFNBR, IFRC, IMD106

NCBI Gene: 3454 ENSG00000142166 UniProt: P17181

The protein encoded by this gene is a type I membrane protein that forms one of the two chains of a receptor for interferons alpha and beta. Binding and activation of the receptor stimulates Janus protein kinases, which in turn phosphorylate several proteins, including STAT1 and STAT2. The protein belongs to the type II cytokine receptor family and functions as an antiviral factor. [provided by RefSeq, Jul 2020]

Primary Disease Associations & Inheritance

Immunodeficiency 106, susceptibility to viral infectionsMIM #619935

Active trials

Pathogenic / LP

407

ClinVar variants

Pubs (1 yr)

0.4

Missense Z

1.21

LOEUF

Clinical Summary— IFNAR1

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Gene-Disease Validity (ClinGen)

immunodeficiency 106, susceptibility to viral infections · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

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Population Constraint (gnomAD)

Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

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ClinVar Variants

85 Pathogenic / Likely Pathogenic· 163 VUS of 407 total submissions

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Clinical Trials

1 active or recruiting trial — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.

1.21LOEUF

pLI 0.000

Z-score 0.75

OE 0.83 (0.59–1.21)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.

0.36Z-score

OE missense 0.94 (0.85–1.04)

270 obs / 287.2 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.

LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.83 (0.59–1.21)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.94 (0.85–1.04)

0≤0.61.4

Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.03

0≤1.21.6

LoF obs/exp: 20 / 24.0Missense obs/exp: 270 / 287.2Syn Z: -0.21

0.73top 25%

GOF

0.6345th %ile

LOF

0.2971th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median

GOFprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.