Is AFG2A p.His503= (c.1509T>C) pathogenic?

AFG2A p.His503= (c.1509T>C) is classified Likely benign in AFG2A (ClinVar, Single submitter, 1 submitter; last evaluated 2025-02-26). Very rare (popmax 0.0022%, sas); Associated with microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome.

How common is AFG2A p.His503= (c.1509T>C) in the general population?

AFG2A p.His503= (c.1509T>C) is very rare (popmax 0.0022%, sas) (gnomAD).

AFG2A p.His503=

Q: What condition is associated with AFG2A p.His503= (c.1509T>C)?

AFG2A p.His503= (c.1509T>C) is associated with microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome (ClinVar).

c.1509T>C · rs771656456 · VCV762333

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.0022%, sas)

Conditions

microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -7.2	GERP -3.4
Overall
CADD	0.463	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0022% South Asian · 2/90,864 alleles

Filtering AF 0.000803% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00065%

Overall 0.00118% 19/1,612,396 alleles · very rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0022%	45,432
Admixed American	0.00167%	59,888
European (non-Finnish)	0.00136%	73,688

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: AFG2A
Protein: p.His503=
Coding: c.1509T>C
MANE Select: NM_145207
dbSNP: rs771656456
Type: single nucleotide variant
Location: chr4:122947283 (GRCh38)
Structure: AlphaFold pLDDT 73.21 · 2 PDB
Residue 503: a UniProt-annotated variant site (in nedhsb)

Full AFG2A gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

AFG2A p.His503Pro Uncertain significance ★ ⚠ same residue
AFG2A p.His503Tyr Uncertain significance ★ ⚠ same residue
AFG2A c.1714+1G>A Pathogenic ★★ same condition
AFG2A c.446+1G>A Likely pathogenic ★★ same condition
AFG2A p.Ala844Val Pathogenic/Likely pathogenic ★★ ⚠ same condition
AFG2A p.Arg445Ter Pathogenic/Likely pathogenic ★★ same condition
AFG2A p.Arg510Ter Pathogenic/Likely pathogenic ★★ same condition
AFG2A p.Arg514Ter Pathogenic/Likely 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/afg2a-p-his503 (accessed [today's date]).

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