Is ATL1 p.Arg446= (c.1338T>C) pathogenic?

ATL1 p.Arg446= (c.1338T>C) is classified Likely benign in ATL1 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2025-07-28). Very rare (popmax 0.000847%, nfe); Associated with hereditary spastic paraplegia 3A.

What condition is associated with ATL1 p.Arg446= (c.1338T>C)?

ATL1 p.Arg446= (c.1338T>C) is associated with hereditary spastic paraplegia 3A (ClinVar).

How common is ATL1 p.Arg446= (c.1338T>C) in the general population?

ATL1 p.Arg446= (c.1338T>C) is very rare (popmax 0.000847%, nfe) (gnomAD).

How is Autosomal dominant spastic paraplegia type 3 inherited?

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

ATL1 p.Arg446=

c.1338T>C · VCV4716981

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 0.000847%, nfe)

Conditions

hereditary spastic paraplegia 3A

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 -0.32	GERP -2.2, phastCons 0.23
Overall
CADD	5.262	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000847% European (non-Finnish) · 10/1,180,032 alleles

Filtering AF 0.000429% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000312%

Overall 0.000684% 10/1,461,894 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: ATL1
Protein: p.Arg446=
Coding: c.1338T>C
MANE Select: NM_015915
Type: single nucleotide variant
Location: chr14:50628249 (GRCh38)
Gene constraint: LOEUF 0.57 · pLI 0.36 · ClinGen HI 0/3 (gnomAD)
Structure: AlphaFold pLDDT 86.49 · 14 PDB
Residue 446: the 'linker' region; an α-helix

Full ATL1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hereditary spastic paraplegia 3A — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Autosomal dominant spastic paraplegia type 3 (Orphanet):

Inheritance: Autosomal dominant
Onset: Adult, Childhood
Prevalence: 1-9 / 1 000 000 (Portugal)

Similar variants

ATL1 p.Arg446Cys Uncertain significance ★ ⚠ same residue
ATL1 p.Arg446Gly Uncertain significance ★ ⚠ same residue
ATL1 p.Arg446His Uncertain significance ★ ⚠ same residue
ATL1 p.Arg217Gln Pathogenic/Likely pathogenic ★★ same condition
ATL1 p.Arg239Cys Pathogenic/Likely pathogenic ★★ same condition
ATL1 p.Arg239His Likely pathogenic ★★ same condition
ATL1 p.Arg403Pro Likely pathogenic ★★ same condition
ATL1 p.Arg415Trp 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/atl1-p-arg446 (accessed [today's date]).

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