Is AP3B1 p.Ile926Val (c.2776A>G) pathogenic?

AP3B1 p.Ile926Val (c.2776A>G) is classified Uncertain significance in AP3B1 (ClinVar, Single submitter, 1 submitter; last evaluated 2022-01-07). AlphaMissense: likely benign (0.0531); Ultra-rare (popmax 0.0154%, sas); Associated with Hermansky-Pudlak syndrome 2.

What condition is associated with AP3B1 p.Ile926Val (c.2776A>G)?

AP3B1 p.Ile926Val (c.2776A>G) is associated with Hermansky-Pudlak syndrome 2 (ClinVar).

How common is AP3B1 p.Ile926Val (c.2776A>G) in the general population?

AP3B1 p.Ile926Val (c.2776A>G) is ultra-rare (popmax 0.0154%, sas) (gnomAD).

How is Familial hemophagocytic lymphohistiocytosis inherited?

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

What do computational predictors say about AP3B1 p.Ile926Val (c.2776A>G)?

AlphaMissense predicts likely benign (score 0.0531) — an in-silico prediction, not a clinical call.

AP3B1 p.Ile926Val

c.2776A>G · rs558325834 · VCV851874

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0531 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0154%, sas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Hermansky-Pudlak syndrome 2

Computational evidence

Protein change
AlphaMissense	0.0531	likely benign
REVEL	0.15	moderately benign-leaning
SaProt	LLR -5.95	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -7.4	GERP -5.5
Regional constraint	o/e 0.91	unconstrained · MANE · 213 kb · p 0.0039 · regional, not allelic
Overall
CADD	0.097	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 0.0154% South Asian · 14/90,618 alleles

Filtering AF 0.00934% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00739%

Overall 0.00162% 26/1,607,642 alleles · ultra-rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0154%	6,473
Admixed American	0.00167%	59,878
European (non-Finnish)	0.000936%	106,791

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: AP3B1
Protein: p.Ile926Val
Coding: c.2776A>G
MANE Select: NM_003664
dbSNP: rs558325834
Type: single nucleotide variant
Location: chr5:78039076 (GRCh38)
Gene constraint: LOEUF 0.59 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 75.85 · 5 PDB

Full AP3B1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Hermansky-Pudlak syndrome 2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Familial hemophagocytic lymphohistiocytosis (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Infancy
Prevalence: 1-9 / 100 000 (Sweden)

Similar variants

AP3B1 c.2078-1G>A Likely pathogenic ★★ same condition
AP3B1 c.280-2A>G Likely pathogenic ★★ same condition
AP3B1 p.Arg104Ter Pathogenic/Likely pathogenic ★★ same condition
AP3B1 p.Arg649Ter Pathogenic/Likely pathogenic ★★ same condition
AP3B1 c.128+4A>G Uncertain significance ★★ same condition
AP3B1 c.2077+6T>C Uncertain significance ★★ same condition
AP3B1 c.2809+4A>G Uncertain significance ★★ same condition
AP3B1 c.2992+3G>A Uncertain significance ★★ 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/ap3b1-p-ile926val (accessed [today's date]).

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