Is HTT p.Ser481Ala (c.1441T>G) pathogenic?

HTT p.Ser481Ala (c.1441T>G) is classified Uncertain significance in HTT (ClinVar, Single submitter, 1 submitter; last evaluated 2021-03-09). AlphaMissense: likely benign (0.0613); Very rare (popmax 0.00267%, afr).

How common is HTT p.Ser481Ala (c.1441T>G) in the general population?

HTT p.Ser481Ala (c.1441T>G) is very rare (popmax 0.00267%, afr) (gnomAD).

What do computational predictors say about HTT p.Ser481Ala (c.1441T>G)?

AlphaMissense predicts likely benign (score 0.0613) — an in-silico prediction, not a clinical call.

HTT p.Ser481Ala

c.1441T>G · rs761970709 · VCV1350975

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0613 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00267%, afr)

Missense predictors

0/2 damaging

AlphaMissense, REVEL · SaProt no call

Computational evidence

Protein change
AlphaMissense	0.0613	likely benign
REVEL	0.024	moderately benign-leaning
SaProt	—	not scored · why
⇒ AlphaMissense and REVEL both call this tolerated; SaProt makes no call.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 0.14	GERP -0.53, phastCons 0.011
Overall
CADD	9.877	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 is an independent agreement signal.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00267% African / African-American · 2/74,944 alleles

Filtering AF 0.000615% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000474%

Overall 0.00149% 24/1,614,084 alleles · very rare exomes 23/1,461,846 · genomes 1/152,238 · joint denominator

Ancestry group	Frequency	1 in
Remaining individualsnot grpmax-eligible	0.008%	12,498
Finnishnot grpmax-eligible	0.00468%	21,348
African / African-Americangrpmax	0.00267%	37,472
Admixed American	0.00167%	60,002
European (non-Finnish)	0.0011%	90,770

Remaining individuals shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

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: HTT
Protein: p.Ser481Ala
Coding: c.1441T>G
MANE Select: NM_001388492
dbSNP: rs761970709
Type: single nucleotide variant
Location: chr4:3127302 (GRCh38)
Structure: AlphaFold pLDDT 85.38 · 30 PDB
Residue 481: an α-helix

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

Similar variants

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HTT p.Arg1654Trp Uncertain significance ★★ same type
HTT p.Arg1945Trp Uncertain significance ★★ same type
HTT p.Asp1157Gly Uncertain significance ★★ same type
HTT p.Asp920Asn Uncertain significance ★★ same type
HTT p.Glu449Ala Uncertain significance ★★ ⚠ same type
HTT p.Gly2084Arg 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/htt-p-ser481ala (accessed [today's date]).

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