Is SYN2 p.Arg186Gln (c.557G>A) pathogenic?

SYN2 p.Arg186Gln (c.557G>A) is classified Uncertain significance in SYN2 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-08-20). AlphaMissense: likely pathogenic (0.8815); Ultra-rare (popmax 0.0164%, mid).

How common is SYN2 p.Arg186Gln (c.557G>A) in the general population?

SYN2 p.Arg186Gln (c.557G>A) is ultra-rare (popmax 0.0164%, mid) (gnomAD).

What do computational predictors say about SYN2 p.Arg186Gln (c.557G>A)?

AlphaMissense predicts likely pathogenic (score 0.8815) — an in-silico prediction, not a clinical call.

SYN2 p.Arg186Gln

c.557G>A · VCV4178477

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.8815 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0164%, mid)

Missense predictors

2/2 damaging

AlphaMissense, SaProt · REVEL indeterminate

Computational evidence

Protein change
AlphaMissense	0.8815	likely pathogenic
REVEL	0.427	indeterminate
SaProt	LLR -13.32	damaging
⇒ AlphaMissense and SaProt both call this damaging; REVEL is indeterminate.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 12	GERP 2.5, phastCons 1
Regional constraint	o/e 1.02	unconstrained · MANE · 186 kb · p 0.66 · regional, not allelic
Overall
CADD	33.0	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean damaging — 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 0.0164% Middle Eastern · 1/6,084 alleles

Filtering AF 0.00437% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00312%

Overall 0.00248% 40/1,613,892 alleles · ultra-rare exomes 37/1,461,676 · genomes 3/152,216 · joint denominator

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.0164%	6,084
Remaining individualsnot grpmax-eligible	0.0112%	8,924
South Asian	0.00878%	11,386
Ashkenazi Jewishnot grpmax-eligible	0.00338%	29,608
Admixed American	0.00333%	30,006
European (non-Finnish)	0.00178%	56,185

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: SYN2
Protein: p.Arg186Gln
Coding: c.557G>A
MANE Select: NM_133625
Type: single nucleotide variant
Location: chr3:12145708 (GRCh38)
Gene constraint: LOEUF 0.539 · pLI 0.90 (gnomAD)
Structure: AlphaFold pLDDT 75.24
Residue 186: the 'c; actin-binding and synaptic-vesicle binding' region

Full SYN2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

SYN2 p.Ala54Val Benign ★★ same type
SYN2 p.Thr506Ala Benign ★★ same type
SYN2 c.1369+21G>C Uncertain significance ★ same type
SYN2 p.Ala302Gly Uncertain significance ★ same type
SYN2 p.Ala546Gly Uncertain significance ★ ⚠ same type
SYN2 p.Arg179Gln Uncertain significance ★ ⚠ same type
SYN2 p.Arg315Trp Uncertain significance ★ ⚠ same type
SYN2 p.Arg328Lys Uncertain significance ★ ⚠ same type

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/syn2-p-arg186gln (accessed [today's date]).

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