Is AMPD2 p.Ala247Val (c.740C>T) pathogenic?

AMPD2 p.Ala247Val (c.740C>T) is classified Uncertain significance in AMPD2 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2023-04-11). AlphaMissense: likely benign (0.061); Ultra-rare (popmax 0.011%, sas); Associated with hereditary spastic paraplegia 63.

What condition is associated with AMPD2 p.Ala247Val (c.740C>T)?

AMPD2 p.Ala247Val (c.740C>T) is associated with hereditary spastic paraplegia 63, pontocerebellar hypoplasia type 9 (ClinVar).

How common is AMPD2 p.Ala247Val (c.740C>T) in the general population?

AMPD2 p.Ala247Val (c.740C>T) is ultra-rare (popmax 0.011%, sas) (gnomAD).

How is Autosomal recessive spastic paraplegia type 63 inherited?

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

What do computational predictors say about AMPD2 p.Ala247Val (c.740C>T)?

AlphaMissense predicts likely benign (score 0.061) — an in-silico prediction, not a clinical call.

AMPD2 p.Ala247Val

c.740C>T · rs145441666 · VCV1309203

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

AlphaMissense

likely benign

0.061 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.011%, sas)

Missense predictors

0/2 damaging

AlphaMissense, REVEL

Conditions

hereditary spastic paraplegia 63

Computational evidence

Protein change
AlphaMissense	0.061	likely benign
REVEL	0.13	moderately benign-leaning
⇒ AlphaMissense and REVEL both call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 0.56	GERP -0.12, phastCons 0.1
Regional constraint	o/e 0.89	unconstrained · MANE · 1,721 bp · p 0.065 · regional, not allelic
Overall
CADD	13.01	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.

⚠ Isoform check: AlphaMissense numbered on a different transcript (AM A301V vs ClinVar A247V) — verify the residue.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.011% South Asian · 10/91,000 alleles

Filtering AF 0.00594% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00454%

Overall 0.00211% 34/1,613,324 alleles · ultra-rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.011%	9,100
African / African-American	0.00401%	24,967
Remaining individualsnot grpmax-eligible	0.0032%	31,208
East Asian	0.00223%	44,896
Admixed American	0.00167%	59,926
European (non-Finnish)	0.00144%	69,404

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: AMPD2
Protein: p.Ala247Val
Coding: c.740C>T
MANE Select: NM_001368809
dbSNP: rs145441666
Type: single nucleotide variant
Location: chr1:109627196 (GRCh38)
Gene constraint: LOEUF 0.705 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 81.28 · 5 PDB
Residue 247: an α-helix

Full AMPD2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hereditary spastic paraplegia 63 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: pontocerebellar hypoplasia type 9

For Autosomal recessive spastic paraplegia type 63 (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy

Similar variants

AMPD2 p.Ala247= Likely benign ★ same residue
AMPD2 c.1698+1G>A Pathogenic/Likely pathogenic ★★ same condition
AMPD2 p.Arg353Ter Pathogenic/Likely pathogenic ★★ same condition
AMPD2 p.Arg449Ter Pathogenic/Likely pathogenic ★★ same condition
AMPD2 p.Arg620His Pathogenic/Likely pathogenic ★★ same condition
AMPD2 p.Arg789His Likely pathogenic ★★ same condition
AMPD2 p.Glu174Ter Pathogenic/Likely pathogenic ★★ same condition
AMPD2 c.1080+3G>A Uncertain significance ★★ 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/ampd2-p-ala247val (accessed [today's date]).

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