Is APRT p.Arg145Ser (c.433C>A) pathogenic?

APRT p.Arg145Ser (c.433C>A) is classified Uncertain significance in APRT (ClinVar, Single submitter, 1 submitter; last evaluated 2018-01-13). AlphaMissense: likely benign (0.2066); Very rare (popmax 0.00133%, afr); Associated with adenine phosphoribosyltransferase deficiency.

What condition is associated with APRT p.Arg145Ser (c.433C>A)?

APRT p.Arg145Ser (c.433C>A) is associated with adenine phosphoribosyltransferase deficiency (ClinVar).

How common is APRT p.Arg145Ser (c.433C>A) in the general population?

APRT p.Arg145Ser (c.433C>A) is very rare (popmax 0.00133%, afr) (gnomAD).

How is Adenine phosphoribosyltransferase deficiency inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

What do computational predictors say about APRT p.Arg145Ser (c.433C>A)?

AlphaMissense predicts likely benign (score 0.2066) — an in-silico prediction, not a clinical call.

APRT p.Arg145Ser

c.433C>A · rs550667813 · VCV887873

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.2066 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00133%, afr)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

adenine phosphoribosyltransferase deficiency

Computational evidence

Protein change
AlphaMissense	0.2066	likely benign
REVEL	0.368	indeterminate
SaProt	LLR -7.19	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL makes no call.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 5.4	GERP 1.6, phastCons 1
Regional constraint	o/e 1.26	unconstrained · MANE · 2,198 bp · p 5.8e-05 · regional, not allelic
Overall
CADD	16.96	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00133% African / African-American · 1/74,932 alleles

Filtering AF 7.9e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 5.4e-05%

Overall 0.0018% 29/1,612,760 alleles · very rare

Ancestry group	Frequency	1 in
Finnishnot grpmax-eligible	0.035%	2,854
Remaining individualsnot grpmax-eligible	0.0032%	31,233
African / African-Americangrpmax	0.00133%	74,932
European (non-Finnish)	0.000339%	295,002

Finnish shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: APRT
Protein: p.Arg145Ser
Coding: c.433C>A
MANE Select: NM_000485
dbSNP: rs550667813
Type: single nucleotide variant
Location: chr16:88809808 (GRCh38)
Gene constraint: LOEUF 1.789 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 96.91 · 16 PDB
Residue 145: an α-helix

Full APRT gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

adenine phosphoribosyltransferase deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Adenine phosphoribosyltransferase deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Adult, Childhood, Elderly, Infancy
Prevalence: 1-9 / 100 000 (Specific population)

Similar variants

APRT p.Arg145His Uncertain significance ★ ⚠ same residue
APRT p.Arg67Gln Likely pathogenic ★★ same condition
APRT p.Arg67Ter Pathogenic ★★ same condition
APRT p.Arg87Ter Pathogenic ★★ same condition
APRT p.Asp65Val Pathogenic ★★ same condition
APRT p.Gly133Arg Likely pathogenic ★★ same condition
APRT p.Gly63Asp Likely pathogenic ★★ same condition
APRT p.Met1Ile Pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/aprt-p-arg145ser (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown