Is MAP2K1 p.Ala26Val (c.77C>T) pathogenic?

MAP2K1 p.Ala26Val (c.77C>T) is classified Uncertain significance in MAP2K1 (ClinVar, Single submitter, 1 submitter; last evaluated 2024-06-11). AlphaMissense: likely benign (0.0937); Very rare (popmax 0.000696%, nfe); Associated with RASopathy.

What condition is associated with MAP2K1 p.Ala26Val (c.77C>T)?

MAP2K1 p.Ala26Val (c.77C>T) is associated with RASopathy (ClinVar).

How common is MAP2K1 p.Ala26Val (c.77C>T) in the general population?

MAP2K1 p.Ala26Val (c.77C>T) is very rare (popmax 0.000696%, nfe) (gnomAD).

What do computational predictors say about MAP2K1 p.Ala26Val (c.77C>T)?

AlphaMissense predicts likely benign (score 0.0937) — an in-silico prediction, not a clinical call.

MAP2K1 p.Ala26Val

c.77C>T · rs1290811972 · VCV2419481

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0937 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.000696%, nfe)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

RASopathy

Computational evidence

Protein change
AlphaMissense	0.0937	likely benign
REVEL	0.469	indeterminate
SaProt	LLR -7.25	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 7.1	GERP 1.3, phastCons 1
Regional constraint	o/e 0.46	unconstrained · MANE · 94 kb · p 1.7e-15 · regional, not allelic
Overall
CADD	24.2	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 0.000696% European (non-Finnish) · 8/1,149,468 alleles

Filtering AF 0.000299% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000216%

Overall 0.00057% 8/1,404,428 alleles · very rare

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: MAP2K1
Protein: p.Ala26Val
Coding: c.77C>T
MANE Select: NM_002755
dbSNP: rs1290811972
Type: single nucleotide variant
Location: chr15:66387424 (GRCh38)
Gene constraint: LOEUF 0.515 · pLI 0.97 · ClinGen HI 0/3 (gnomAD)
Structure: AlphaFold pLDDT 84.05 · 99 PDB
Residue 26: the 'disordered' region

Full MAP2K1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

RASopathy — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

MAP2K1 p.Ala26Thr Uncertain significance ★★ ⚠ same residue
MAP2K1 p.Arg108Leu Likely pathogenic ★★★ same condition
MAP2K1 p.Asn122Asp Pathogenic ★★★ ⚠ same condition
MAP2K1 p.Asp67Asn Pathogenic ★★★ same condition
MAP2K1 p.Glu203Gly Pathogenic ★★★ same condition
MAP2K1 p.Leu42Arg Likely pathogenic ★★★ same condition
MAP2K1 p.Leu42Phe Pathogenic ★★★ same condition
MAP2K1 p.Leu92Arg 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/map2k1-p-ala26val (accessed [today's date]).

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