NMRK1

Chr 9

nicotinamide riboside kinase 1

Also known as: C9orf95, NRK1, bA235O14.2

NCBI Gene: 54981 ENSG00000106733 UniProt: Q9NWW6

Nicotinamide adenine dinucleotide (NAD+) is essential for life in all organisms, both as a coenzyme for oxidoreductases and as a source of ADP-ribosyl groups used in various reactions. Nicotinic acid and nicotinamide, collectively known as niacin, are the vitamin precursors of NAD+. Nicotinamide riboside kinases, such as NRK1, function to synthesize NAD+ through nicotinamide mononucleotide using nicotinamide riboside as the precursor (Bieganowski and Brenner, 2004 [PubMed 15137942]).[supplied by OMIM, Mar 2008]

Active trials

Pathogenic / LP

ClinVar variants

Pubs (1 yr)

0.3

Missense Z

1.49

LOEUF

Clinical Summary— NMRK1

⚡

Population Constraint (gnomAD)

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

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ClinVar Variants

38 Pathogenic / Likely Pathogenic· 38 VUS of 76 total submissions

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.

1.49LOEUF

pLI 0.000

Z-score 0.26

OE 0.92 (0.59–1.49)

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.

0.33Z-score

OE missense 0.91 (0.77–1.08)

93 obs / 102.3 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.0.92 (0.59–1.49)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.91 (0.77–1.08)

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.0.88

0≤1.21.6

LoF obs/exp: 12 / 13.0Missense obs/exp: 93 / 102.3Syn Z: 0.57

0.6938th %ile

GOF

0.5955th %ile

LOF

0.2386th %ile

The highest-scoring mechanism for this gene is dominant-negative.

DNprediction 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.