NAPRT
Chr 8nicotinate 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.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
The highest-scoring mechanism for this gene is gain-of-function.
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
215 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 0 | 55 | 0 | 55 |
Likely Pathogenic | 0 | 0 | 5 | 0 | 5 |
VUS | 1 | 103 | 5 | 0 | 109 |
Likely Benign | 0 | 6 | 0 | 1 | 7 |
Benign | 0 | 0 | 1 | 1 | 2 |
| Total | 1 | 109 | 66 | 2 | 178 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View 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.
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools