Is ALPL p.Cys497Arg (c.1489T>C) pathogenic?

ALPL p.Cys497Arg (c.1489T>C) is classified Likely pathogenic in ALPL (ClinVar, Single submitter, 1 submitter; last evaluated 2025-08-29). AlphaMissense: likely pathogenic (0.9622); Absent from gnomAD v4.1; Associated with hypophosphatasia.

What condition is associated with ALPL p.Cys497Arg (c.1489T>C)?

ALPL p.Cys497Arg (c.1489T>C) is associated with hypophosphatasia (ClinVar).

How common is ALPL p.Cys497Arg (c.1489T>C) in the general population?

ALPL p.Cys497Arg (c.1489T>C) is absent from gnomAD v4.1 (gnomAD).

How is Hypophosphatasia inherited?

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

What do computational predictors say about ALPL p.Cys497Arg (c.1489T>C)?

AlphaMissense predicts likely pathogenic (score 0.9622) — an in-silico prediction, not a clinical call.

ALPL p.Cys497Arg

c.1489T>C · VCV4086907

Likely pathogenic Single submitter

Classification

Likely pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.9622 · ACMG-weighted

gnomAD v4.1

Not reported

no allele count reported in gnomAD v4.1 (AN 1,604,498)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

hypophosphatasia

Computational evidence

Protein change
AlphaMissense	0.9622	likely pathogenic ✓ concordant with ClinVar
REVEL	0.761	pathogenic-leaning
SaProt	LLR -11.37	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 6.2	GERP 1.8, phastCons 1
Regional constraint	o/e 0.83	unconstrained · MANE · 24 kb · p 6.1e-06 · regional, not allelic
Overall
CADD	24.4	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

No allele count reported in gnomAD v4.1 (AN 1,604,498). This is missing data, not an absence: the variant may or may not be present in gnomAD. Rarity (ACMG PM2) and BA1/BS1 cannot be assessed for it.

Variant & gene context

Gene: ALPL
Protein: p.Cys497Arg
Coding: c.1489T>C
MANE Select: NM_000478
Type: single nucleotide variant
Location: chr1:21577562 (GRCh38)
Gene constraint: LOEUF 0.987 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 93.74 · 5 PDB
Residue 497: a turn; a disulfide bond

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

Disease context

hypophosphatasia — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Hypophosphatasia (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive
Onset: All ages

Similar variants

ALPL p.Cys497Ser Likely pathogenic ★★ same residue
ALPL p.Cys497Tyr Uncertain significance ★ same residue
ALPL c.1190-2A>T Pathogenic ★★ same condition
ALPL c.182-1G>A Pathogenic/Likely pathogenic ★★ same condition
ALPL c.182-2A>G Pathogenic/Likely pathogenic ★★ same condition
ALPL c.297+1G>A Pathogenic/Likely pathogenic ★★ same condition
ALPL c.298-1G>A Pathogenic ★★ same condition
ALPL c.472+1G>A 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/alpl-p-cys497arg (accessed [today's date]).

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