Is AMPD2 c.91+1G>T pathogenic?

AMPD2 c.91+1G>T is classified Likely pathogenic in AMPD2 (ClinVar, Single submitter, 1 submitter; last evaluated 2024-04-30). Very rare (popmax 8.48e-05%, nfe); Associated with hereditary spastic paraplegia 63.

What condition is associated with AMPD2 c.91+1G>T?

AMPD2 c.91+1G>T is associated with hereditary spastic paraplegia 63, pontocerebellar hypoplasia type 9 (ClinVar).

How common is AMPD2 c.91+1G>T in the general population?

AMPD2 c.91+1G>T is very rare (popmax 8.48e-05%, nfe) (gnomAD).

How is Autosomal recessive spastic paraplegia type 63 inherited?

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

AMPD2 c.91+1G>T

VCV3574021

Likely pathogenic Single submitter

Classification

Likely pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

canonical splice-site (±1/±2)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 8.48e-05%, nfe)

Conditions

hereditary spastic paraplegia 63

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation/SpliceAI carries the signal.
Consequence	canonical splice-site (±1/±2)	predicted loss-of-function
Splicing
Splice region	donor +1	canonical splice dinucleotide (donor +1) · inside the BP7-excluded zone
SpliceAI	Δ0.91	donor loss, 1 bp away · raw score · deltas
Pangolin	Δ0.79	loss · gain 0.03 · agrees with SpliceAI · independent
Constraint at this position
Conservation	phyloP 12	GERP 1.7, phastCons 1
Overall
CADD	34.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 8.48e-05% European (non-Finnish) · 1/1,179,528 alleles

Overall 6.85e-05% 1/1,460,258 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: AMPD2
Coding: c.91+1G>T
MANE Select: NM_001368809
Type: single nucleotide variant
Location: chr1:109621267 (GRCh38)
Gene constraint: LOEUF 0.705 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 81.28 · 5 PDB

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 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
AMPD2 c.353+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-c-91-plus-1g-t (accessed [today's date]).

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