Is CRPPA p.Val170Ile (c.508G>A) pathogenic?

CRPPA p.Val170Ile (c.508G>A) is classified Uncertain significance in CRPPA (ClinVar, Single submitter, 1 submitter; last evaluated 2022-02-04). AlphaMissense: likely benign (0.1591); Absent from gnomAD v4.1; Associated with autosomal recessive limb-girdle muscular dystrophy type 2U.

What condition is associated with CRPPA p.Val170Ile (c.508G>A)?

CRPPA p.Val170Ile (c.508G>A) is associated with autosomal recessive limb-girdle muscular dystrophy type 2U, muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 7 (ClinVar).

How common is CRPPA p.Val170Ile (c.508G>A) in the general population?

CRPPA p.Val170Ile (c.508G>A) is absent from gnomAD v4.1 (gnomAD).

How is ISPD-related limb-girdle muscular dystrophy R20 inherited?

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

What do computational predictors say about CRPPA p.Val170Ile (c.508G>A)?

AlphaMissense predicts likely benign (score 0.1591) — an in-silico prediction, not a clinical call.

CRPPA p.Val170Ile

c.508G>A · rs762819997 · VCV941435

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1591 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

autosomal recessive limb-girdle muscular dystrophy type 2U

Computational evidence

Protein change
AlphaMissense	0.1591	likely benign
REVEL	0.342	indeterminate
SaProt	LLR -8.77	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL makes no call.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 4.8	GERP 4.1, phastCons 1
Regional constraint	o/e 1.14	unconstrained · MANE · 330 kb · p 0.001 · regional, not allelic
Overall
CADD	22.3	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.

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: CRPPA
Protein: p.Val170Ile
Coding: c.508G>A
MANE Select: NM_001101426
dbSNP: rs762819997
Type: single nucleotide variant
Location: chr7:16406087 (GRCh38)
Gene constraint: LOEUF 1.462 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 88.63 · 1 PDB
Residue 170: an α-helix

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

Disease context

autosomal recessive limb-girdle muscular dystrophy type 2U — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 7

For ISPD-related limb-girdle muscular dystrophy R20 (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood, Infancy

Similar variants

CRPPA p.Val170Gly Uncertain significance ★ ⚠ same residue
CRPPA c.1120-1G>T Pathogenic ★★ same condition
CRPPA c.258-1G>C Pathogenic/Likely pathogenic ★★ same condition
CRPPA c.835+2T>C Pathogenic/Likely pathogenic ★★ same condition
CRPPA p.Arg184Ter Pathogenic ★★ same condition
CRPPA p.Arg268Ter Pathogenic ★★ same condition
CRPPA p.Gln215Ter Pathogenic/Likely pathogenic ★★ same condition
CRPPA c.1026+5G>C 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/crppa-p-val170ile (accessed [today's date]).

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