PYCR3
Chr 8pyrroline-5-carboxylate reductase 3
Also known as: PYCRL
The protein catalyzes the final step in proline biosynthesis, reducing pyrroline-5-carboxylate to proline using NADH/NADPH, and is specifically involved in the ornithine-to-proline biosynthetic pathway. Biallelic mutations cause autosomal recessive hypomyelinating leukodystrophy-10, presenting in infancy with severe developmental delays, hypotonia, seizures, and progressive brain atrophy. The gene shows low constraint to loss-of-function variation, consistent with the recessive inheritance pattern observed clinically.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
The highest-scoring mechanism for this gene is dominant-negative.
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
148 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 | 0 | 62 | 9 | 0 | 71 |
Likely Benign | 0 | 2 | 0 | 1 | 3 |
Benign | 0 | 0 | 0 | 0 | 0 |
| Total | 0 | 64 | 69 | 1 | 134 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
PYCR3 · 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