Is SETX p.Lys556= (c.1668G>A) pathogenic?

SETX p.Lys556= (c.1668G>A) is classified Likely benign in SETX (ClinVar, Single submitter, 1 submitter; last evaluated 2019-12-31). Very rare (popmax 0.00167%, amr); Associated with amyotrophic lateral sclerosis type 4.

What condition is associated with SETX p.Lys556= (c.1668G>A)?

SETX p.Lys556= (c.1668G>A) is associated with amyotrophic lateral sclerosis type 4, spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 2 (ClinVar).

How common is SETX p.Lys556= (c.1668G>A) in the general population?

SETX p.Lys556= (c.1668G>A) is very rare (popmax 0.00167%, amr) (gnomAD).

How is Amyotrophic lateral sclerosis type 4 inherited?

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

SETX p.Lys556=

c.1668G>A · rs1328865930 · VCV725887

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00167%, amr)

Conditions

amyotrophic lateral sclerosis type 4

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 0.6	GERP -0.034, phastCons 1
Overall
CADD	6.067	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00167% Admixed American · 1/60,020 alleles

Overall 6.2e-05% 1/1,614,180 alleles · very rare exomes 1/1,461,832 · genomes 0/152,348 · joint denominator

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: SETX
Protein: p.Lys556=
Coding: c.1668G>A
MANE Select: NM_015046
dbSNP: rs1328865930
Type: single nucleotide variant
Location: chr9:132329930 (GRCh38)
Gene constraint: LOEUF 0.442 · pLI 1.00 (gnomAD)
Structure: AlphaFold pLDDT 52.93

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

Disease context

amyotrophic lateral sclerosis type 4 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 2

For Amyotrophic lateral sclerosis type 4 (Orphanet):

Inheritance: Autosomal dominant
Onset: Adolescent, Childhood

Similar variants

SETX p.Lys556Arg Conflicting classifications of pathogenicity ★ ⚠ same residue
SETX p.Arg111Ter Pathogenic ★★ same condition
SETX p.Arg1363Ter Pathogenic ★★ same condition
SETX p.Arg1606Ter Pathogenic ★★ same condition
SETX p.Arg1778Ter Pathogenic/Likely pathogenic ★★ same condition
SETX p.Arg2098Ter Pathogenic ★★ same condition
SETX p.Arg332Trp Pathogenic/Likely pathogenic ★★ same condition
SETX p.Arg778Ter 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/setx-p-lys556 (accessed [today's date]).

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