NAPRT

Chr 8

nicotinate phosphoribosyltransferase

Also known as: NAPRT1, PP3856

Nicotinic acid phosphoribosyltransferase catalyzes the first step in NAD biosynthesis from nicotinic acid, converting nicotinic acid and 5-phospho-D-ribose 1-phosphate to beta-nicotinate D-ribonucleotide in an ATP-dependent reaction. Biallelic mutations cause pellagra-like dermatitis with neurologic and psychiatric manifestations, inherited in an autosomal recessive pattern. The gene shows tolerance to loss-of-function variants, consistent with the recessive inheritance pattern of associated disease.

OMIMResearchSummary from RefSeq, UniProt
GOFmechanismLOEUF 1.43
Clinical SummaryNAPRT
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.43LOEUF
pLI 0.000
Z-score -0.16
OE 1.03 (0.761.43)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
-0.62Z-score
OE missense 1.10 (1.001.21)
331 obs / 300.9 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE1.03 (0.761.43)
00.351.4
Missense OE1.10 (1.001.21)
00.61.4
Synonymous OE1.13
01.21.6
LoF obs/exp: 27 / 26.1Missense obs/exp: 331 / 300.9Syn Z: -1.21
DN
0.6163th %ile
GOF
0.6737th %ile
LOF
0.3260th %ile

The highest-scoring mechanism for this gene is gain-of-function.

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.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

NAPRT · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →